This paper proposes methods to incorporate firm heterogeneity in the standard IO-table based approach to portray the domestic segment of global value chains in a country. Using Chinese firm census data for both manufacturing and service sectors, along with constrained optimization techniques, we split the conventional IO table into sub-accounts, which are used to estimate direct and indirect domestic value added in exports of different types of firm. We find that in China, both state-owned enterprises (SOEs) and small and medium domestic private enterprises (SMEs) have much higher shares of indirect exports and ratios of value-added exports to gross exports (VAX), compared to foreign-invested and large domestic private firms. Based on IO tables for both 2007 and 2010, we find increasing VAX ratios for all firm types, particularly for SOEs. By extending the method proposed by Antràs et al. (2012), we find that SOEs are consistently more upstream while SMEs are consistently more downstream within industries. These findings suggest that SOEs still play an important role in shaping China’s exports.