This study investigated the role of early language ability in the development of math skills among Chinese kindergarteners. The participants were 2012 6-year-old children from 60 kindergartens in South China. They were tested on both informal and formal math skills. The informal math testing focused on basic number concepts such as object counting, while the formal math testing involved numerical calculations such as addition and subtraction. The children’s language and non-verbal reasoning abilities were also assessed. Correlational analysis showed that the children’s language ability was more strongly associated with informal than formal math skills. Hierarchical regression analyses revealed that the children’s language ability could uniquely predict both informal and formal math skills, with age, gender, and non-verbal intelligence statistically controlled. However, language ability predicted more variance of informal math skills than of formal math skills. The findings indicate that children’s language ability may have different roles on the development of formal and informal math skills.