Hi Li,
I didn't checked it by myself but I think the following should work: the editor implements the interface IEditLayers which contains the property CurrentLayer. This is the layer the user selected to add the new feature:
Dim uid As UID
uid = New UIDClass()
uid.Value = "esriEditor.Editor"
Dim editor As IEditor
editor = CType(m_application.FindExtensionByCLSID(uid), IEditor)
Dim editLayers as IEditLayers
editLayers = CType(editor, IEditLayers)
Dim layer as ILayer
layer = editLayers.CurrentLayer
et voila ....
Frank
