Abstract The main purposes of this study are: 1. to illuminate the evolutions of science education in American primary and junior high schools; 2. to analysis the orientations of science educational primary and junior high schools in contemporary America; 3. to make some suggestions for improving Chinese science education of primary and junior high schools. According to the findings, some suggestions are presented: 1. to reinforce the accultrative function of science education; 2. to reinforce the value education in science teaching; 3. to provide some real problems in life to studends, so that they would get some experiences of science research; 4. to cultivate the teachers' humanistic attitude.