The evolution of networks in rural industrial clusters, in particular in the context of China has been paid more attention to in the world. Applying the theory and techniques of social network analysis (SNA), this study is with particular regard to the business network relationships and their evolutionary dynamics of steel measuring tape manufacturing clustered in Nanzhuang Village, Yucheng County of Henan Province, China, which is important for better understanding the industrial and regional development in less developed rural areas. From data collected by comprehensive questionnaire survey in 2002 and mass interviews with 60 enterprises and assembling families and several government authorities in 2002, 2003, 2004, 2005 and 2008, four types of networks are identified: spin-off, consulting, communication and cooperative. The characteristic of these networks is outlined in detail. Compared with the high-tech clusters of typical developed areas, the networks that have evolved in traditional manufacturing clusters are more affected by emotive linkages. The cluster networks are shown to exhibit a polycentric hierarchical structure. The family relationships are the dominate spin-off channels of enterprises, while the supply and demand relationships and the mobility of the skilled workers are also important paths of network learning, and the cooperation relationships are comparatively stable. Besides the root enterprises, the middle-sized enterprises are comparatively more active than small-sized enterprises, and the intermediary agencies and the service institutions act as bridges of the inter-enterprises cooperation. By analysis of the structure of networks and the interactions between the networks, the four stages of network evolution are also identified. The four stages are dominated by the family networks, the internal division production networks, the local innovation networks and the global supply networks respectively, and they play different roles in cluster development.