As the transfer platform of knowledge, strategic alliance which is a kind of expression form of innovation network has gained extensive attention and research gradually. The effect of network structure characteristics on knowledge transfer activities is also influenced by the enterprise geographic space position. This paper takes the Chinese biopharmaceutical industry 1995-2010 strategic alliance data as a sample, using negative binomial regression model, to study the influence of network proximity and geographical proximity on knowledge transfer performance. Because the alliance network structure characteristics can change the flow properties of resources and information in the geographical neighboring enterprises, this paper further studied the influence of geographical proximity on alliance knowledge transfer performance under the regulation of network density .The research results show that geographic proximity between enterprises can promote alliance knowledge transfer significantly, but network proximity didn’t have significantly influence .Higher network density can improve the promoting function of geographical proximity to knowledge transfer. This paper also puts forward some suggestions on the present situation of China's biological pharmaceutical industry strategic alliances.