This paper examines China's domestic production networks. It uses VAT invoices to build inter-provincial input-output tables for 2002 and 2012. These are combined with population censuses to determine the location of workers involved in production. We document i) increased trade in intermediate inputs between provinces; ii) inter-provincial production fragmentation that differs by product; iii) substitution of domestic for foreign intermediates, resulting in increased domestic value added in exports. Information about the occupations of workers suggest that iv) richer coastal areas such as Beijing, Tianjin, and Shanghai specialize in R&D and marketing activities, whereas v) inland provinces specialize in production activities.