AIM: To study 3-6 years old children's refraction, providing information for prevention and treatment of the preschool children's ametropia.

METHODS: A sample of 2 848 children from 30 kindergartens were selected randomly. Refraction was performed using SureSight vision screening instrument, and to investigate the parents questionnaire survey of related factors. Date collection was analyzed statistically.

RESULTS:Totally 2848 preschool children were participated in the survey, 2 565 of them were qualified to complete the questionnaire, the completion rate was 90.06%. The overall refractive abnormality rate was 18.13%. The detection rate of abnormal refraction in four age groups was: 11.84%, 16.28%, 20.72%, 25.62%. χ² test for trend(χ²=47.085, P<0.01)showed that the abnormal refraction detection rate increased with age trend. Refractive abnormality rate of 21.83% in boys, 13.54% in girls, the difference was statistically significant(χ²=29.378, P<0.01). The non-conditional Logistic regression analysis, parents' educational level, maternal age, premature birth, birth asphyxia, birth weight, father diopter, eye using time, eat fruits and vegetables and other factors of OR value was respectively: 2.638, 2.380, 2.316, 5.891, 9.675, 3.146, 2.079, 1.241, 6.731.

CONCLUSION: Along with the growth of the age, refraction anomaly detection rate increasing tendency. The boy's refractive abnormality rate was significantly higher than that of girls. Parents with low education level, maternal age, birth asphyxia, premature, weighing less than 2 000g or higher than 4 000g, father ametropia, long time with eyes close, eating less fruits and vegetables are the risk factors for ametropia.