Abstract: Taking the export product quality as the starting point, this paper uses the reduction of import tariff and the relaxation of FDI control to express the opening of intermediate input products in manufacturing and service industries, so as to discuss the synergistic effect of trade liberalization of intermediate goods in manufacturing and service industries on the improvement of export product quality. Firstly, it elaborates the occurrence mechanism of the synergistic effect by constructing an endogenous selection model of the quality of intermediate input export products, including the manufacturing industry and the service industry; on this basis it conducts an empirical test to verify the existence of the synergistic effect. The results of the heterogeneity analysis show that, except for the transportation industry, the finance, telecommunication, wholesale and retail industries all have synergistic effect with the reduction of intermediate input tariff in the manufacturing industry. There exists a synergistic effect between the deregulation of FDI intermediate input with equity restriction, examination and approval and other restrictions, while the synergistic effect of the relaxation of key personnel restriction is not significant. In addition, it is also found that the synergy effect is more significant in the enterprises with lower productivity, but in the foreign-funded enterprises and the processing trade enterprises, it is weaker.

Key words: the service industry, intermediate inputs, synergistic effect, export, quality