The purpose of this study is to investigate the current situation of sport social support of 5th and 6th graders in Guang Hwa elementary school, to compare the impacts in background variation on social support and to compare the impacts of different amount of physical activity on social support of 5th and 6th graders in Guang Hwa elementary school. The object of study are 5th and 6th graders of Guang Hwa elementary school in school year of 2010. This study uses stratified ransom sampling and the self-made measurement table called "The Social Support of 5th and 6th graders of Guang Hwa elementary school" as research tool, getting of 532 valid measurement tables. The collected data will be analyzed and presented in descriptive statistic analysis, T test, one-way ANOVA, LSD multiple comparisions to conduct the analysis. The conclusions are as follow: 1. The average of general social support is 3.25, it reaches middle-high level. 2. In the field of different genders, there is significant difference on Classmate and Friend Support. The girls get more Classmate and Friend Support than boys. 3. In the field of body mass index, there is no significant difference in all factors. 4. In the field of the amount of physical activity, there is significant difference on classmate and friend support, family support, teachers' support and general social support. And the amount of high-physical activity is better than the amount of middle-physical activity and the amount of low-physical activity.