Abstract: The effective operation of the innovation ecosystem depends on the efficient collaboration of all partners in the governance mechanism. Based on contract governance and relationship governance, a tripartite evolutionary game model including platform enterprises and complementary enterprises is constructed. The conditions of the behavior stability of the game subjects are analyzed, and the key influencing factors are discussed by numerical simulation. The results show that the minimum excess returns obtained by complementary enterprises determine their strategic choice, and the change of R&D investment of either side will change the minimum excess returns accepted by participants. Incentive mechanism is a necessary prerequisite for complementary enterprises to participate in the innovation cooperation network. Platform enterprises with strong network relationships will significantly improve the cooperation willingness of complementary enterprises, and the two parties in a weak relationship can reach cooperation by a third party which has strong relationship with both. 

Key words: innovation ecosystem, governance mechanism, tripartite game, evolutionary game