BACKGROUND: Human milk oligosaccharides (HMOs) are a group of breast milk carbohydrates exerting pivotal benefits for breastfed infants. Whether maternal diet is associated with breastmilk HMO composition has not been well-characterized. OBJECTIVES: We investigated the associations between dietary nutrient intake and HMO concentrations in a general pregnant and postpartum population. METHODS: A total of 383 breast milk samples and the corresponding food frequency questionnaires during 0-400 postpartum days from 277 mothers were collected. Six different HMOs were detected in mothers' milk. The correlation between nutrients and HMOs were analyzed using a linear mixed-effects model. RESULTS: We found plant nutrients, vitamin A, vitamin C and vegetables as positive predictors of 3-fucosyllactose; vitamin B1 and vitamin B2 were positive predictors for 2'-fucosyllactose level and the sum of 2'-fucosyllactose and 3-fucosyllactose; tocopherol and metal elements were positive predictors for 3'-sialyllactose; and metal elements were positively associated with the sum of all the six HMOs; the milk and lactose intake was a positive predictor of lacto-N-tetraose levels and the sum of lacto-N-tetraose and lacto-N-neotetraose. CONCLUSIONS: The results show that vegetables, vitamins and metal elements are dietary components positively associated with HMO concentrations.