This study investigated the basic characteristics of loneliness and its relationship with depression，mental health，self-esteem and social support of 198 elderly residents in Beijing. The loneliness status of the elderly residents in Beijing is above the middle level. Demographic characteristics （gender，location，marital status，education level，monthly income，family location，household registration，number of children） had significant impact on elderly residents’ loneliness. The loneliness of the elderly decreases with the increase of mental health，self-esteem and social support. Elderly residents’ loneliness is negatively correlated with mental health，self-esteem and social support，but not with depression.