Large-size class in primary and secondary schools had been a challenging and long-lasting problem in some areas of China. Under the impetus of the Ministry of Education，local governments started to address this problem since 2015. Yiyang County of Jiangxi Province was successful in solving the problem by promoting rural education quality and regulating urban school enrollments. Based on the investigations of large size class in eastern，central and western China，the causes of large size class were analyzed and policy suggestions to solve the problem were put forward.