The purpose of this study was to evaluate the effect of zinc administration on the autistic children. the subject diagnosed as infantile autism were 24 male and 10 female children of a special school in Taegu city. Control group were selected from 1 : 2 ratio matched with cases on sex and age. The results were as follows. In female autistic group, the mean content of zinc in hair was significantly lower than control group, but in male the result was inverse at all age group. The content of zinc in hair showed significant correlation with age in male autistic group and control group. Zinc content of hair, age and sex accounted for 37.2% of the variance of autistic score and the most significant variable was zinc content. Autistic group were divided into two group. Group I which zinc content of hair below 150 ppm were administrated with multi-vitamin contained 10mg of zinc, Group II which zinc content of hair above 150 ppm were administrated with placebo. Total administration period was eight weeks. In zinc administration group, there was a decreasing tendency of autistic score as the zinc content of hair was increased but the relationship was not statistically significant.