Hi,i'm wondering if there is a possibility to build objects in 3D with topology ? i know that Brep basically support topology but can't find that in AutoCAD 2015 ? does it really work with topology ? if not is there a CAD software that does ? 

You can create node, network, or polygon topologies using AutoCAD Map 3D.

Ok thank you, i actually meant to say : do CAD softwares respect topology structure of 3D data in storage or exchange ? otherwise how can we verify that they do ?

I have no idea what you mean by the phrase "in storage or exchange."

i mean does DXF and DWG support topology ? i know that STEP does