At the beginning of the reform period, though informal institutions as a substitute for formal institutions efficiently promoted the development of private enterprises, it eroded and destroyed the authority and execution efficiency of formal institutions with guanxi behaviors and implicit rules. With the progress of marketization, how to restrain and guide the evolution of informal institutions is an unavoidable obstacle for the development of private enterprises— transforming their competitive strategy from “non-market” dominance to “market” dominance. Based on survey data of 2,628 private enterprises from 31 provinces in China, we establish a regional commercial culture index to empirically investigate the different influences of guanxi behavior between entrepreneurs of different ages and regional guanxi culture. The results show that, compared with entrepreneurs who started businesses in recent years, i.e., after the 1990s, those who started businesses during the 1970s and the 1980s are more dependent on guanxi behaviors. Meanwhile, the higher the level of education, the less an entrepreneur is likely to be dependent on guanxi behaviors. However, compared with the constraint of the degree of regional marketization, regional guanxi culture promotes entrepreneurs’ guanxi behaviors. Further research indicates that the more enterprises depart from regional guanxi culture, the stronger the ability to innovation. This study can not only enrich the institutional analysis of entrepreneurs’ guanxi behaviors, but also provide a theoretical foundation for further expansion and deepening of reform.