Objective: To examine the prospective association between peripubertal diet quality and pubertal timing. Methods: Multivariate regression analyses were performed using data obtained from 1 588 SCCNG (Southwest China Childhood Nutrition and Growth) study participants, which included dietary data, anthropometric parameters, and information about potential confounders during peri puberty, two and four years before the onset of menarche or voice break. Dietary intake in peri puberty was assessed using a validated food frequency questionnaire. Diet quality was determined using the Chinese Children Dietary Index (CCDI), which measures adherence to current dietary recommendations. Age at menarche or voice break (M/VB) were used as pubertal markers. Results: The CCDI score ranged from 58.0 to 132.5 for girls and from 48.3 to 129.9 for boys. The pubertal markers consistently indicated that girls and boys with a higher peripubertal diet quality entered puberty later than their counterparts with lower CCDI scores (higher vs. lower CCDI tertiles: age at M was 13.1 years (11.2-13.3) and 12.5 years (12.0-13.9)(P<0.01); VB was 13.8 years (12.1-14.8) and 13.4 years (12.5-15.1)（P=0.03), after adjusting for paternal education level, energy intake, and pre pubertal body fat. Conclusion Children with a higher diet quality during peri puberty entered puberty at a later age. Dietary guidance and intervention are needed for better dietary quality among children during pubertal transition.