diff --git a/addons/account/project/report/cost_ledger.py b/addons/account/project/report/cost_ledger.py
index 225a85d2ee1..c7423675c15 100644
--- a/addons/account/project/report/cost_ledger.py
+++ b/addons/account/project/report/cost_ledger.py
@@ -37,75 +37,67 @@ class account_analytic_cost_ledger(report_sxw.rml_parse):
             'sum_credit': self._sum_credit,
             'sum_balance': self._sum_balance,
         })
+        self.children = {}      # a memo for the method _get_children
 
-    def _lines_g(self, account_id, date1, date2):
+    def _get_children(self, accounts):
+        """ return all children accounts of the given accounts
+            :param accounts: list of browse records of 'account.analytic.account'
+            :return: tuple of account ids
+        """
+        analytic_obj = self.pool.get('account.analytic.account')
+        res = set()
+        for account in accounts:
+            if account.id not in self.children:
+                self.children[account.id] = analytic_obj.search(self.cr, self.uid, [('parent_id', 'child_of', [account.id])])
+            res.update(self.children[account.id])
+        return tuple(res)
+
+    def _lines_g(self, account, date1, date2):
         self.cr.execute("SELECT sum(aal.amount) AS balance, aa.code AS code, aa.name AS name, aa.id AS id \
                 FROM account_account AS aa, account_analytic_line AS aal \
-                WHERE (aal.account_id=%s) AND (aal.date>=%s) AND (aal.date<=%s) AND (aal.general_account_id=aa.id) AND aa.active \
-                GROUP BY aa.code, aa.name, aa.id ORDER BY aa.code", (account_id, date1, date2))
+                WHERE (aal.account_id IN %s) AND (aal.date>=%s) AND (aal.date<=%s) AND (aal.general_account_id=aa.id) AND aa.active \
+                GROUP BY aa.code, aa.name, aa.id ORDER BY aa.code", (self._get_children([account]), date1, date2))
         res = self.cr.dictfetchall()
-
         for r in res:
-            if r['balance'] > 0:
-                r['debit'] = r['balance']
-                r['credit'] = 0.0
-            elif r['balance'] < 0:
-                r['debit'] = 0.0
-                r['credit'] = -r['balance']
-            else:
-                r['debit'] = 0.0
-                r['credit'] = 0.0
+            r['debit'] = r['balance'] if r['balance'] > 0 else 0.0
+            r['credit'] = -r['balance'] if r['balance'] < 0 else 0.0
         return res
 
-    def _lines_a(self, general_account_id, account_id, date1, date2):
+    def _lines_a(self, general_account, account, date1, date2):
         self.cr.execute("SELECT aal.name AS name, aal.code AS code, aal.amount AS balance, aal.date AS date, aaj.code AS cj FROM account_analytic_line AS aal, account_analytic_journal AS aaj \
-                WHERE (aal.general_account_id=%s) AND (aal.account_id=%s) AND (aal.date>=%s) AND (aal.date<=%s) \
+                WHERE (aal.general_account_id=%s) AND (aal.account_id IN %s) AND (aal.date>=%s) AND (aal.date<=%s) \
                 AND (aal.journal_id=aaj.id) \
-                ORDER BY aal.date, aaj.code, aal.code", (general_account_id, account_id, date1, date2))
+                ORDER BY aal.date, aaj.code, aal.code", (general_account['id'], self._get_children([account]), date1, date2))
         res = self.cr.dictfetchall()
-
         for r in res:
-            if r['balance'] > 0:
-                r['debit'] = r['balance']
-                r['credit'] = 0.0
-            elif r['balance'] < 0:
-                r['debit'] = 0.0
-                r['credit'] = -r['balance']
-            else:
-                r['debit'] = 0.0
-                r['credit'] = 0.0
+            r['debit'] = r['balance'] if r['balance'] > 0 else 0.0
+            r['credit'] = -r['balance'] if r['balance'] < 0 else 0.0
         return res
 
-    def _account_sum_debit(self, account_id, date1, date2):
-        self.cr.execute("SELECT sum(amount) FROM account_analytic_line WHERE account_id=%s AND date>=%s AND date<=%s AND amount>0", (account_id, date1, date2))
-        return self.cr.fetchone()[0] or 0.0
+    def _account_sum_debit(self, account, date1, date2):
+        return self._sum_debit(self, [account], date1, date2)
 
-    def _account_sum_credit(self, account_id, date1, date2):
-        self.cr.execute("SELECT -sum(amount) FROM account_analytic_line WHERE account_id=%s AND date>=%s AND date<=%s AND amount<0", (account_id, date1, date2))
-        return self.cr.fetchone()[0] or 0.0
+    def _account_sum_credit(self, account, date1, date2):
+        return self._sum_credit(self, [account], date1, date2)
 
-    def _account_sum_balance(self, account_id, date1, date2):
-        debit = self._account_sum_debit(account_id, date1, date2)
-        credit = self._account_sum_credit(account_id, date1, date2)
+    def _account_sum_balance(self, account, date1, date2):
+        debit = self._account_sum_debit(account, date1, date2)
+        credit = self._account_sum_credit(account, date1, date2)
         return (debit-credit)
 
     def _sum_debit(self, accounts, date1, date2):
-        ids = map(lambda x: x.id, accounts)
-        if not ids:
-            return 0.0
-        self.cr.execute("SELECT sum(amount) FROM account_analytic_line WHERE account_id IN %s AND date>=%s AND date<=%s AND amount>0", (tuple(ids), date1, date2,))
+        self.cr.execute("SELECT sum(amount) FROM account_analytic_line WHERE account_id IN %s AND date>=%s AND date<=%s AND amount>0",
+            (self._get_children(accounts), date1, date2,))
         return self.cr.fetchone()[0] or 0.0
 
     def _sum_credit(self, accounts, date1, date2):
-        ids = map(lambda x: x.id, accounts)
-        if not ids:
-            return 0.0
-        self.cr.execute("SELECT -sum(amount) FROM account_analytic_line WHERE account_id IN %s AND date>=%s AND date<=%s AND amount<0", (tuple(ids),date1, date2,))
+        self.cr.execute("SELECT -sum(amount) FROM account_analytic_line WHERE account_id IN %s AND date>=%s AND date<=%s AND amount<0",
+            (self._get_children(accounts), date1, date2,))
         return self.cr.fetchone()[0] or 0.0
 
     def _sum_balance(self, accounts, date1, date2):
-        debit = self._sum_debit(accounts, date1, date2) or 0.0
-        credit = self._sum_credit(accounts, date1, date2) or 0.0
+        debit = self._sum_debit(accounts, date1, date2)
+        credit = self._sum_credit(accounts, date1, date2)
         return (debit-credit)
 
 report_sxw.report_sxw('report.account.analytic.account.cost_ledger', 'account.analytic.account', 'addons/account/project/report/cost_ledger.rml',parser=account_analytic_cost_ledger, header="internal")
diff --git a/addons/account/project/report/cost_ledger.rml b/addons/account/project/report/cost_ledger.rml
index d53467b4e93..7500b655ab3 100644
--- a/addons/account/project/report/cost_ledger.rml
+++ b/addons/account/project/report/cost_ledger.rml
@@ -229,28 +229,28 @@
       </tr>
     </blockTable>
     <section>
-      <para style="terp_default_2">[[ repeatIn(objects,'o') ]]</para>
+      <para style="terp_default_2">[[ repeatIn(objects,'account') ]]</para>
       <blockTable colWidths="56.0,273.0,70.0,70.0,70.0" style="Table_Account_Detail">
         <tr>
           <td>
-            <para style="terp_default_Bold_9">[[ o.code ]]</para>
+            <para style="terp_default_Bold_9">[[ account.code ]]</para>
           </td>
           <td>
-            <para style="terp_default_Bold_9">[[ o.complete_name ]]</para>
+            <para style="terp_default_Bold_9">[[ account.complete_name ]]</para>
           </td>
           <td>
-            <para style="terp_Default_Bold_Right_9_U">[[ formatLang (account_sum_debit(o.id,data['form']['date1'],data['form']['date2'])) ]] </para>
+            <para style="terp_Default_Bold_Right_9_U">[[ formatLang (account_sum_debit(account,data['form']['date1'],data['form']['date2'])) ]] </para>
           </td>
           <td>
-            <para style="terp_Default_Bold_Right_9_U">[[ formatLang (account_sum_credit(o.id,data['form']['date1'],data['form']['date2'])) ]] </para>
+            <para style="terp_Default_Bold_Right_9_U">[[ formatLang (account_sum_credit(account,data['form']['date1'],data['form']['date2'])) ]] </para>
           </td>
           <td>
-            <para style="terp_Default_Bold_Right_9_U">[[ formatLang (account_sum_balance(o.id,data['form']['date1'],data['form']['date2']))]] [[ company.currency_id.symbol ]]</para>
+            <para style="terp_Default_Bold_Right_9_U">[[ formatLang (account_sum_balance(account,data['form']['date1'],data['form']['date2']))]] [[ company.currency_id.symbol ]]</para>
           </td>
         </tr>
       </blockTable>
       <section>
-        <para style="terp_default_2">[[ repeatIn(lines_g(o.id,data['form']['date1'],data['form']['date2']),'move_g') ]]</para>
+        <para style="terp_default_2">[[ repeatIn(lines_g(account,data['form']['date1'],data['form']['date2']),'move_g') ]]</para>
         <blockTable colWidths="56.0,273.0,70.0,70.0,70.0" style="Table_Move_Line_Detail">
           <tr>
             <td>
@@ -271,7 +271,7 @@
           </tr>
         </blockTable>
         <section>
-          <para style="terp_default_2">[[ repeatIn(lines_a(move_g['id'],o.id,data['form']['date1'],data['form']['date2']),'move_a') ]]</para>
+          <para style="terp_default_2">[[ repeatIn(lines_a(move_g,account,data['form']['date1'],data['form']['date2']),'move_a') ]]</para>
           <blockTable colWidths="56.0,56.0,217.0,70.0,70.0,70.0" style="Table_Move_Line_Content">
             <tr>
               <td>
@@ -302,4 +302,4 @@
     </section>
     </pto>
   </story>
-</document>
\ No newline at end of file
+</document>