AIM:To obtain the basic data of the myopia prevalence at primary school in Zhongshan city,especially to obtain the relationship between myopia and cornea,vitreous and ocular axis. METHODS:According to the myopia criteria of Eye Encyclopedia of China,cluster sampling was adopted to make the study sample.Ocular vision,corneal curvature, anterior chamber length,lens lengths and vitreous length were conducted with ARK-30/AR-20 automatic refractive instrument/cornea curvance and STRONG 6000AB portable ocular A/B ultrasonic on these samples. RESULTS:With the increase of age,the prevalence of students with myopia increased.The length of vitreous and ocular axis were not related with myopia. CONCLUSION:With the age raises,the incidence of myopia increases.The deepening of myopia,the increase of anteroposterior diameter of axial length.