Abstract: Under network convergence, firms can provide multiple products and services based on original network infrastructure. The paper establishes a multiproduct pricing model in light of the actual background of network converge of the communications industry. The following findings are obtained. When a firm hold monopolistic positions in multiple network industries, a social planner considering network externality will set a price lower than one not considering the externality. If a monopoly moves into a related industry in the form of a bundle, it may press down the price of the bundle and dispel the incumbent from the related market. The implications of the findings are significant. As for multi-market price regulation, regulator should have an eye on network externality and multi-market strategic interaction among firms.