This paper uses data of birth、mortality and census to estimate school-age population and the gross enrollment rates of primary，junior and senior secondary education from 2000 to 2014，to compare the estimated and official gross enrollment rates，and finds that the official gross enrollment ratios was much overestimated.Because the data of students are all from the government，we conclude that the overestimated gross enrollment rates of government stem from underestimated school-age population.Our estimated gross enrollment rates of primary，junior and senior secondary education were 99.8%,87.9% and 69.7% respectively in 2014，about 12% junior secondary school-age and 30% senior secondary school-age population were out of school.The goal of all children obtaining nine-year compulsory education has not been attained，and achieving a universal senior secondary education has a long way to go.