Objective:To determine the prevalence and compare the related factors of depressive symptoms among urban primary school students in Hefei and Shenzhen.Methods:Participants from Hefei and Shenzhen were asked to fill out the questionnaires including Children's Depression Inventory(CDI)and items of Social Support and demography.Results:The prevalence of depressive symptoms was significantly higher among the participants in Hefei(11.9%)than that in Shenzhen(8.2%)(?2 =10.37,P=0.001).The students with depressive symptoms had significant lower social support scores than those with no depressive symptoms in Hefei and Shenzheng cities(Parents support score was 3.6?1.6 vs 5.0?0.9,school support score was 2.1?0.9 vs 2.6?0.8,peer support score was 3.2?1.5 vs 4.4?1.0,total support score was 8.9?2.9 vs 12.0?1.8 in Hefei.Parents support score was 3.4?1.8 vs 4.9?0.7,school support score was 2.2?1.2 vs 2.9?0.8,peer support score was 3.4?1.5 vs 4.4?0.9,total support score was 9.0?2.7/12.3?1.6 in Shenzheng,all P