Abstract: This paper presents an OCP-communication based hw/sw co-modeling method in the SoC virtual component level design.By the method,we create a virtual component level model-FIT M (Function Interface-Timing Model).The virtual component level's model acts between system level's algorithm model and RTL's cycle accurate model,to simplify the mapping from system level's task to RTL's architecture.FIT M-based co-simulation can compromise the accuracy and speed of co-simulation,to effectively solve the problem that system level's simulation is not accurate enough and RTL's simulation is too slow.The result from co-simulation can support the decision of hw/sw partition and the analysis of the SoC system's performance.In order to make the hw/sw model in the virtual component level independent of RTL's bus protocol,we use the open core protocol's transaction communication protocol,to substantially improve the reusability of the model.Finally,the FIT M of Digital Soldier Audio/Video Decoder SoC is demonstrated.