中国科技论文在线 ormance? This paper focus on the strategy commitment with uncertain cost and uncertain joint innovation level, and analyze its impact to cooperation innovation behavior. This paper also puts forward the 35 concept of state dependent commitment, and find out that strategy commitment can decrease effect from uncertainty, increase innovation input and improve cooperation performance, especially for the upstream firms. This paper theoretically proposes strategy commitment’s positive role in cooperation innovation, especially in stimulating supplier in participating in the new product development and research. 40 Key words: supply chain management; technology innovation; innovation alliance; commitment; opportunism