Relationships between exposure to preschool education and children's academic and social outcomes have been documented in Western countries. There is a lack of comparable research in China, where preschool education is relatively formal, but rather flexible in arrangement. We conducted research at six public kindergartens in a large Chinese city (Beijing), involving 342 Chinese preschoolers (188 boys, 154 girls, M age?=?60.45 months) and their middle-class parents and teachers. We examined the influence of preschool education exposure (assessed by age of entry and hours of attendance per week) on children's literacy, numeracy, and classroom behaviour problems. Hierarchical multiple regression analyses found that entering preschools at a younger age and staying there for a longer time benefited children's academic development, but longer attendance was also linked to slightly more behaviour problems. Specifically, beginning a full-day preschool education (i.e. eight to nine hours) for five days at ages two to three would likely enhance the overall development of all children. Earlier entry age and higher intensity of attendance in preschools specifically benefitted the numeracy skills of children from families with lower middle income or somewhat lower education levels in Beijing.