The purpose of this study is to investigate the impact of the expanded audit report adoption on the value relevance of accounting information and the moderating effect of audit quality on this relationship. The results first suggest that the value relevance of earnings was significantly increased after the expanded audit report adoption. We further utilize the Oaxaca-Blinder decomposition model to decompose the difference in stock prices between the pre- and post-adoption periods into the part that can be explained by the endowment effect and the part that can be explained by the coefficient effect. The results show that the stock prices' increase is primarily due to an increase in equity book value and earnings and an increase in the regression coefficient of earnings. We also find that the positive relationship between stock prices and accounting information is mitigated by audit quality.