Abstract: This paper selected 165 high-tech firms from Chinese Pear River Delta region as empirical research samples for studying the relationships among enterprise knowledge inertia, knowledge integration and new product development performance. The results show that enterprise experiential inertia not only take direct positive effect on new product development performance, but also take indirect positive effect on it through external and internal knowledge integration. At the same time, although enterprise procedural inertia and informational inertia take no direct effect on new product development performance, procedural inertia can impact on it through external and internal of knowledge integration, and informational inertia can impact on it through external knowledge integration. In addition, the knowledge integration including external and internal are both take direct positive effect on new product development significantly.