Abstract: Social capital plays an important role in high and new technology industry cluster. Its function can be seen in the fol-lowing aspects:it affects the position, development speed and information communication of high and new technology industry cluster, and promotes the cooperation between corporations in the cluster; it can solve effectively the problem of contract shortage in the technical innovation network of hi-tech corporations; it is useful in helping the cluster develop from the embryonic stage to pri-mary stage; it is helpful in promoting the cluster to realize knowledge transfer, flow and creation, and so on.