Hi Hari,
Still i'm not clear with answer, are you sure, that you are capitalizing Asset on WBS element instead of Cost center, and posting depreciation to WBS element. Please check your asset master record Time Dependent Tab, and verify that, did you have capitalized any asset on WBS element or not, I assumed you didn't.
Please also use this report S_ALR_87012060 - List of Origins by Cost Elements gives WBS & all cost elements, execute the report and double click for detail.
Please also check Depreciation Simulation with Planned Investments:
http://help.sap.com/saphelp_45b/helpdata/en/2a/f9f90e493111d182b70000e829fbfe/content.htm
Regards
Javed