Abstract: Based on the data from China Industry Business Performance Data and China Customs Trade Database, this paper conducts a measurement of the domestic value-added rate (DVAR) of the enterprises’ export in the manufacturing industry and empirically analyzes the impact of economic agglomeration of Yangtze River Economic Belt on the export upgrading of regional manufacturing industry and its action mechanism. The results show that economic agglomeration has significantly promoted the DVAR of export of manufacturing enterprises, and this effect is better in the regions with higher level of economic agglomeration. In the upper-middle reaches of Yangtze River, the promotion effect brought by the economic agglomeration is not ideal, while the effect is significant in the lower reaches of Yangtze River and the central cities there along the river. Meanwhile, economic agglomeration helps to improve the DVAR of general trade and mixed trade exports. It is also possible that trade processing enterprises will be pushed to transform into general trade enterprises with higher added value. The results of the mechanism tests indicate that it is through promoting the regional information development and increasing the input ratio of domestic intermediate products that economic agglomeration can increase the DVAR of exports. Furthermore, regional economic agglomeration can help to expand the domestic intermediate products market and deepen the international participation of enterprises. In terms of external influences, the maturity of factor markets and the improvement of market services can also help to strengthen the promoting effect of economic agglomeration on the upgrading of manufacturing exports.

Key words: economic agglomeration, Yangtze River Economic Belt, domestic value-added rate of exports, information development, domestic intermediate products input