Abstract:Due to important role of marketing networks in the process of maturation of industrial clusters, this study aims to design a model of marketing network formation in Iran’s industrial clusters context. Applying a grounded theory approach, we interviewed with the clusters promotion agents and managers involved in the networks, and collected organizational documents, as required by the study. Using open, axial and selective coding technique, a model of marketing network has been formed. Results show that the shared motivation of partners to solve common problems or exploit marketing opportunities is the main cause of the formation of marketing network. Marketing networks include a wide range of formal and informal networks that are formed during five stages; the inception, formation of initial core, tension, organizing and action. The cultural, historical and institutional context of cluster, personality of managers/ owners, characteristics of network promoter agent and firms' structural characteristics affect networking activities. The major advantages of networking are reducing marketing costs and stimulating competitiveness among the network members. The findings also suggest that strengthening networking capabilities, may help the managers to promote their own businesses .