This study compared the effects of science teaching methods between teacher-led small group based on the teacher`s plan and child-led small group based on the children`s plan. Specific variables included (1) the achievement and the variation of science activities, (2) the continuing time of science activies, and (3) the function of communication among peers during science activities. The subjects were 60 kindergarten children. Data were collected by the event sampling observation using a video tape recorder. Descriptive analysis and χ²-test were used on the data concerning achievement and variation of science activities. T-test was used on the continuing time of science activities, and χ²-test was used on the competence of communication among peers. The results showed that the child-led small group was superior to the teacher-led small group on (1) the achievement and the variation of science activities, (2) the continuing time of science activities, and (3) the competence of communication among peers during science activities. The results suggest that in science teaching, the method of child-led small group should be applied to kindergarten in order to improve children`s scientific and communication competence.