Abstract: To uncover how international R&D alliance affects radical innovation of the alliance enterprise, this paper puts forward a series of hypotheses among alliance type, knowledge pool, alliance network and radical innovation of the alliance enterprise by reviewing relevant documentations. We analyzed 224 alliances composed by 74 Chinese enterprises during 2000-2010 using a negative binomial regression model based on panel data.The results of this study show that R&D collaboration can significantly improve radical innovation but negatively affected by Joint-Venture. Interestingly, knowledge pool can positively affect the radical innovation and moderates the relationship between alliance type and radical innovative performance of the alliance enterprises. Additionally, close network relations are an important factor promoting radical innovation. This study offers a new guidance for the alliance enterprises to promote radical innovative ability.