This study attempts to develop integrated activities of musical education and science education, investigates the effects of the integrated activities on children`s musical concepts. The integrated activities were designed by researchers and composed by 2 steps. Research question were as follows : 1) How was composed integrated activities of musical education and science education? 2) What was the effect of integrated activities? The subjects of this study for research question 1 were 10 children and the subjects of this study for research question 2 were 40 children of 4 years of age from two classes at D, S kindergarten in Seoul city. Twenty children were in the experimental group and twenty in the control group. The integrated activities were used over a 3-week period. The musical concept test were administered and analyzed by ANCOVA with SPSS/pc program. The study results showed that 1) The integrated activities of musical education and science education were developed and the subjects were interested in the activities and involved in the activities. 2) The integrated activities of musical education and science education increased children`s musical concepts significantly.