  To understand what does Chern-Simons with compact Lie group(does not like
Dijkgraaf-Witten model with finite group in 3d) attach to a point, we first
give a construction of Topological Quantum Field Theory(TQFT) via Chern-Simons
theory in this paper. We discuss the Topological Quantum Field Theory and
Chern-Simons theory via Category, then interpret the cobordism as cospan and
field of space-time as span, which ultimately deduce the construction of TQFT.
