Objective To explore the relationship between quality of life and social support in senile dementia patients. Methods A matched case-control study was used to collect 80 senile dementia patients and 80 healthy elderly people. They were assessed with general situation questionnaire, Quality of Life in Alzheimer's Disease (QOL-AD) and Social Support Revalued Scale (SSRS). Results There was significant difference in QOL-AD between 2 groups (P<0.01). The score of objective support, subjective support, and total social support was lower in senile dementia patients than in healthy elderly people (P<0.05), but there was no significant difference in support utilization (P>0.05). The score of family, marriage, the overall experience of life, quality of life was positively correlated with the score of subjective support and total social support (P<0.05), the score of emotion was negatively correlated with the score of subjective support (P<0.05), the score of living conditions and family was positively correlated with the score of objective support (P<0.05). Conclusion Senile dementia patients obtained poor social support and lived in lower quality.