High participation systems (HPS) of higher education (HE) are common throughout the world. The consequences of HE expansion has attracted enough academic attention; however, much less discussed is the impact of the HE expansion on retaking the college entrance examination. Drawing upon China's provincial panel data, a battery of econometric methods, and the effectively maintained inequality theory, this paper explores whether and how HE expansion influences the retake rate of college entrance examinations. Estimation results suggest that HE expansion leads to an increase in retake rates. For every unit increase in HE expansion intensity, the retake rate increases by 0.014 percentage points. This is an unintended impact of HE expansion on retake rates in the context of increased access to HE worldwide and an overall decline in retake rates worldwide. Above findings still hold after an array of robustness checks. This positive relationship is more prominent in provinces with more key higher education institutions (HEIs) than in provinces without key HEIs. This implies the diploma devaluation of ordinary HEIs might be one of the reasons for the increase in retake rates due to HE expansion. The findings of this paper will be informative for economies that have experienced HE expansion.