Abstract: Given the increasingly significant resource & environment constraints, revitalizing domestic green technologies and promoting their transfer and application has become a key for China to achieve the "dual carbon" goal. Based on the data of green technology patent transfers in the Yangtze River Delta, this paper empirically tests the carbon emission reduction effect and the transmission mechanism of inter-city green technology transfer (GTT). This study finds that:(1) GTT can significantly suppress regional carbon emissions, and there is a lag period; (2) The mediating effect of industrial structure changes is mainly reflected in "advanced-quality" and "rationalization", but the "advanced-quantity" does not play a significant mediating effect; (3) The improvement of R&D level plays a mediating effect by alleviating the distortion of R&D human and capital allocation, and improving the R&D capability; (4) The emission reduction demonstration effect of the "internal" type of GTT within the same city is lower than that of the "external" type's cross-city transfer. We further point out pragmatic ways to curb carbon emissions, such as focusing on "demand-driven supply, supply-creating demand", promoting the quantity and quality of GTT, accelerating its embedding in industrial chain, transforming its demonstration effect into a scale effect, and promoting the linkage of elements among talent chain, capital chain, and innovation chain.

Key words: green technology transfer, carbon emission, Yangtze River Delta, mediating effect