In recent years,the intensification of trade protectionism caused by the trend of'anti-globalization'has made China's external environ-ment face great uncertainty.This article takes China's accession to the WTO at the end of 2001 as a quasi-natural experiment.Based on the data-base of China's industrial enterprises,this article uses the differences-in-differences method to study the impact of trade policy uncertainty on the markup dispersion.The main conclusions are as follows:(1)The decrease of trade policy uncertainty will reduce the dispersion of markup dispersion,which is still valid after a series of robustness and effectiveness tests.(2)The impact of trade policy uncertainty on the markup dispersion can be realized through increasing exports and reducing VAT.(3)The impact of trade policy uncertainty on the markup dispersion varies with industry type,ownership and region.This article provides implication for the development of Chinese enterprises and foreign trade policy making.