Abstract: Objective To investigate the association between psychological stress and serum level of 8-hydroxy-2'-deoxyguanosine(8-OHdG) among Yao and Zhuang residents in Baiku area of Guangxi Zhuang Autonomous Region(Guangxi).Methods A total of 164 Yao and 160 Zhuang farmers in Baiku area of Guangxi were surveyed with demo-graphy and life style questionnaire,Life Event Scale(LES),Symptom Checklist-90(SCL-90),and Social Support Rating Scale(SSRS).Serum 8-OHdG level of the residents was measured with enzyme-linked immunosorbent assay(ELISA).Results For all the residents,the ratio of with the life events score of more than 20 was 32.41%;the detection rate of psychological problems was 26.12% and the average score of social support was 8.55±1.69.The average anxiety level of Zhuang residents was higher than that of Yao residents(1.66±0.69 vs.1.43±0.42) and the average anxiety level of female residents was higher than that of male residents(1.65±0.66 vs.1.44±0.46),with significant differences(P<0.05 for all).The average level of serum 8-OHdG was 0.28±0.10 ng/mL.The 8-OHdG levels of the residents with different ethnic,education level,and age were significantly different(P<0.05).The 8-OHdG level was positively correlated with somatization,anxiety and depression,but negatively correlated with social support utilization degree and social support scores(P<0.05).In multivariate regression analyses,somatization(b=0.035,β=3.625,P<0.01) and social support utilization degree(b=-0.204,β=-2.192;P<0.05)entered the equation and could explain 9.60% of the variance.Conclusion Serum 8-OHdG level is correlated with psychological stress and social support and could be used as an early biological indicator of psychological stress among Yao and Zhuang residents in Guangxi.