Objective: To investigate visual acuity of pupils of grade 4-6 in Liaoning Province in 2019 and to analyze its influencing factors, and to provide the scientific basis for myopia prevention and intervention. Methods: A total of 16 716 students of grade 4-6 in 14 cities of Liaoning Province were selected by multi-stage stratified random cluster sampling, and the long-range visual acuity and refraction was evaluated and a questionnaire survey was conducted. Logistic regression analysis was used to analyze the in-fluencing factors of myopia in primary school students. Results: The myopic rate of grade 4-6 pupils in Liaoning Province was 49.17%. Multiple Logistic regression analysis found that the main factors affecting vision included urban and rural division, sex, recess, restriction of electronic products usage from parents, and heredity(OR=0.93, 1.29, 0.90, 0.82, 3.12, 1.61, 1.64, P<0.05). Among them, rural areas, outdoor activity during recess and restriction of electronic product usage from parents was associated with lower risk of myopia, in contrast, being girl and parental myopia was associated with higher risk of myopia. Conclusion The incidence of myopia among primary school students in Liaoning Province is relatively high, exterting high pressure on prevention and control. In order to prevent myopia in primary school students, Composite interventions should be developed including change students’ lear-ning style, eliminate unhealthy living habits and targeted propaganda and education.