[영문]We study the impact of maternal care on early child development using an expansion in Canadian maternity leave entitlements. Following the leave expansion, mothers who took leave spent 48?58 percent more time not working in their children’s first year of life. This extra maternal care primarily crowded out home-based care by unlicensed nonrelatives and replaced full-time work. Our estimates suggest a weak impact of this increase in maternal care on indicators of child development. For example, measures of temperament and motor and social development show changes that are small and statistically insignificant.