Abstract: China's metropolitan strategy expressed in a focalized way is the expansion of provincial capitals. This article explores the phenomenon of provincial capitals expansion and analyses its impact on economic growth. Firstly, it constructs the indexes of relative population growth and depicts the characteristics of provincial capital expansion based on permanent resident population data. Then it further analyzes the theoretical mechanism of the influence of provincial capital expansion on provincial economic growth, and uses the panel data of 25 provinces from 2006 to 2016 to conduct an empirical test. The findings show that the issue of provincial capital expansion is prominent and is still going on, that provincial capital expansion has significantly promoted the provincial economic growth measured by per capita GDP, that the causality is still stable after replacing per capita GDP index with the average satellite light gray and purifying the total factor productivity, and that provincial capital expansion has no inverted-U-type impact on provincial economic growth. The conclusion of this article can provide enlightenment for the implementation of metropolitan strategy at the provincial level.

Key words: provincial capital expansion, economic growth, satellite lighting, total factor productivity