Abstract: Objective to learn the relationship between mental health and social support among elderly people living alone and to provide evidence for improving their life quality.Methods With the Self-Rated Health Measurement Scale Version1.0(SRHMS),a case-control study was conducted among 63 elderly people living alone and 112 controls from 18 communities in Kunming.Results The scores of the cases in mental health and positive feelings were 5.78±1.68,6.32±2.29,which were significantly lower than that of controls(6.59±1.4,7.49±1.76,P<0.01).The scores of cases in role activities/social adjustment,social resources/social contact and social support were 6.13±1.72,5.51±2.24, 5.52±1.91,which were significantly lower than that of ontrols(7.14±1.76,6.79±1.81,6.37±1.61,P<0.01).Conclusion　Mental healthine lderly people living a lone is not good and social support needs to be streng thened.