Objectives : This study reports a massive vision screening on preschool children of Yangsan city in Kyungnam Province. Methods : From March to July 2012, we conducted vision and color test on 1,409 preschool children aged from one to six and used Auto Kerato-Refractometer(KR-8900) on children with naked vision below 0.5 in order to detect the cause of poor vision. Written form of test result is filled and distributed to each parents. Uncooperative 195 children were excluded and the rest were statistically analyzed by using SPSS version 18.0 program. Results : 16 children(1.1%) had dyschromatopsia and the number of boys was threefold higher than that of girls. The average visual acuity was 0.8 to 0.9 regardless of age. 45 children(3.8%) showed myopia, 82 children showed hyperopia(6.8%), 4 children showed anisometropia(0.3%), among which 16 children were wearing glasses. Conclusions : This study has a great significance that a massive preschool vision screening was carried out by Korean medicine hospital for the first time.