Abstract: Objective To determine visual acuity and refractive state among preschool children in Haikou,as to provide basic information for eyesight care and guidance.Methods From June 2015 to October 2016,visual acuity and refractive status of 3 654 preschool children aged 3 to 6 from randomly selected 20 kindergartens in Haikou were assessed using visual acuity chart(<4 years old),or logarithmic visual acuity chart and 5-point record (≥ 4 years old).Refractive status was evaluated by using Welch Allyn's Suresight vision screening instrument (United States).Positive screening children were informed to visit ophthalmologic clinic for further examination.Results The detection rate of abnormal vision among preschool children in Haikou was 16.58%,significant decreasing with age (x2 =29.75,P<0.05).A total of 146 (4.3%) children diagnosed with amblyopia.Simple hyperopia and mixed hyperopic with astigmatism were the most common type of abnormal vision among children in Haikou,which both showed decreasing trend with age.Conclusion Abnormal vision is common among preschool children in Haikou,which needs more attention on early detection,prevention and intervention.