Spatio-Temporal properties are the intrinsic properties of Cyber-Physical System(CPS),the correlation in space and time between computing and physical entities should be fully considered in CPS modeling process in order to guarantee the correctness of system state and behavior.Based on the functional extension of Colored Petri Net(CPN),the formal definition of Open Colored Petri Net(OCPN) is proposed.Then the definition of CPS physical entity and the algorithm to construct the corresponding OCPN model are proposed.This method can effectively describe the position evolution of the physical entity by representing the space information with space tokens.In addition,the interaction between entity and environment is represented by Spatio-Temporal event tokens.Then the modules of CPS physical entities are assembled to the OCPN model of whole application.To show the effectiveness of the approach,an intelligent square system is introduced as a case study.