A total 147 cases of malignant tumors in children under 15 years of age who admitted Presbyterian Medical Center, Keimyung University for 6 years from Jan. 1973 to Dec. 1978 were analyzed clinically and the following results were obtained. 1) The incidence of malignancies on all admitted cases was 1.7% and the annual incidence was 1.4~2.0% without any annual increase of incidence on childhood malignancies. 2) The highest age incidence of childhood malignancy was noted in 1~5 years of age group(36.7%) 3) Males were more affected with the male to female ratio 1.8:1 4) Leukemia was the most common form of childhood malignancy(47.6%) followed by brain tumor (10.9%) and lymphoma (8.2%) in order. 5) Acute leukemia, retinoblastoma, wilm's tumor and neuroblastoma were seen most before the age og 5years. The lymphoma, brain tumor, and bone tumor have tendency to increase the incidence over the age of 5years. 6) Out of 147 cases of childhood malignancies, 102 cases(69.3%) have visited the pediatric department for first time. The common malignanies seeking pediatrician were accure leukemia, wilm's tumor, and neuroblastoma. 7) Out of 70 cases of acute leukemia, 32 cases(45.7%) were lymphocytic, 12 cases(17.1%), were myelogenous, and 15 cases (21.4%) were unclassified leukemia.