Abstract: The innovative ability is more and more important for International Joint Ventures(IJV) building and maintaining its competitive advantage, a great deal of studies about factors affecting IJV were done by scholars, but there are no scholars who touch the two factors of cluster and the network. How network affected innovation capability of IJV within cluster is reached, and empirical research was done by using 96 samples of IJV in South China region. The results indicate that network, such as network strength, network density, and the degree of mutual relations is important to the innovation ability of IJV situated in clusters, and it is a key factor for IJV bringing full advantage of cluster into play. Key words: cluster; network; innovation of IJVs