Abstract: Purpose/Significance Can strengthening accountability improve government performance? The answer is still controversial and needs to be tested. After the 18th National Congress of the Communist Party of China, the CPC Central Committee implemented comprehensive and strict governance of the party and strengthened accountability, which provided a new opportunity for natural experiment to answer this question. Design/Methodology Based on the tracking survey data of Chinese families from 2010 to 2016, this paper uses the breakpoint regression method to test the impact and path of strengthening accountability on government performance by taking the changes of county and district government performance in China before and after the central government strengthened accountability in 2013 as the analysis object. Conclusions/Findings It is found that the implementation of strengthening accountability significantly improves government performance in the short term, and the intermediary effects of responsiveness, service, fairness and standardization of government behavior are significant. However, the influence of strengthening accountability on government performance shows an inverted U development trend, and the sustainability is poor. Based on the national macro data, the analysis based on natural experiments and the interview data of grass-roots civil servants, this paper responds to the debate on the “effectiveness” and “ineffectiveness” of accountability in academic circle, provides a preliminary explanation of the causes of the debate, and a new perspective for understanding the impact of accountability on government performance.