Existing studies on the impact of adult child migration on health of left-behind elderly are not consistent. Using two waves of China Family Panel Studies data ( CFPS 2010＆2012) ，this paper re-examines the impact of migration of adult children on the health of left-behind elderly in rural China，and investigates if the role of family support is an important mechanism. To account for the potential selection bias，propensity score matching analysis is conducted for robust check. Results indicate that a- dult children's migration was detrimental to rural elderly's health. A lack of care support and emotional support due to child migration primarily accounted for this negative effect. We did not find the critical role of financial support on the health of elderly parents，probably because it cannot be easily transformed into healthy benefits.