Data were used from the 1991–2009 China Health and Nutrition Survey to examine the influence of informal care on labor market outcomes for married women of working aged, with emphasis on caregiving intensity. After accounting for potential endogeneity between caregiving and labor force participation (LFP) through simultaneous equations modeling, caregivers who provided more than 15 or 20 hr of caregiving per week were 4.5–7.7% less likely to be LFPs. Intensive caregivers who remained working had significantly lower (4.97–7.20) weekly hours of work. The significant positive effect of informal care on LFP only existed in the rural sample, and these women also had much lower hours of work than their urban counterparts. Opportunities exist for policy interventions that target intensive caregivers in order to allow them to balance both work and caregiving.