Loneliness is a serious problem for older people, which can be alleviated by social support. The dramatic population ageing together with social and economic change in China increases the likelihood of loneliness and the availability of different sources of social support of older people. The aim of this review was to identify the prevalence of loneliness and its related factors and sources of social support of older people in China. Electronic literature searches were conducted in September 2011 using Web of Science, PsycINFO, MEDLINE, PubMed, CINAHL, China Academic Journal and VIP Database for Chinese Technical Periodicals. Twenty-six papers were identified and reviewed. The prevalence of loneliness varied across the studies, reflecting the different measurements and samples. Marital status, gender, age, educational level, economic level, living arrangements, health status and social support were significant factors related to loneliness. The family was the most important source of social support followed by friends. The receipt of family support improved subjective well-being and mental health, but the effects of support from friends were inconsistent. Chinese older people received relatively little support from neighbours, governmental or other social organisations. Further well-designed studies are needed to identify additional factors related to loneliness and to understand the support from friends, neighbours, formal organisations and other sources.