Abstract: This study treats the demonstration-zone policy of whole agricultural industry-chain development as a quasi-natural experiment and employs the difference-in-differences method to examine the impact of this policy on the county-level industrial structure upgrading. The findings indicate that the whole agricultural industry-chain construction has a significant positive influence on the county-level industrial structure upgrading and that the former promotes the latter through entrepreneurial activity. The study reveals that the effects of the policy are more pronounced in those industries such as transportation,warehousing and postal services,information transmission software and information technology services,real estate,leasing and business services,and education. Furthermore,the impact is particularly significant in the eastern and central regions of China. These conclusions provide valuable empirical evidence and policy reference for promoting the high-quality development of county-level industries and the regional industrial structure upgrading.

Key words: the demonstration-zone of whole agricultural industry-chain development, county-level industrial structure upgrading, entrepreneurial activity, high-quality development