Abstract: Objective To investigate the food and water intake during the first 3 days postpartum and analyze risk factors for the delayed onset of lactation among women in Guangzhou. Methods Data were collected from September 2013 to May 2014 in Guangzhou Women and Children's Medical Center. Three 24-hour dietary recalls (1 to 3 days postpartum) and questionnaire survey were conducted to collect food intake, demographic characteristic, maternal reproductive history, gestational age, delivery mode, postpartum analgesia, birth weight, feeding behaviors and condition of newborns of the delivery women. Factors associated with the delayed onset of lactation were identified with univariate and multivariate logistic regressions. Results Of the 237 pairs of delivery women and newborns, 204 participated in the study. The mean age of delivery women was (28.31±3.32) years. Among the participants, 98.0% were the Han nationality, 81.9% had the educational level at college or above, 75.5% were on the job during the pregnancy, 86.3% were primiparas, and 69.6% had natrural delivery. After delivery, proportions of three major macronutrients of protein, carbohydrates, and fat mothers took were 16.68%, 55.96%, and 27.60%, respectively, consistent with the ratios of 13%-15%, 50%-65%, and 20%-30% recommended by DRIs. Except eggs (104.4%), intakes of other food and water were below the recommended intakes. The consumptions of dairy (6.7%), fruits (21.0%), vegetables (21.0%), and bean products (26.7%) were at the lowest level. In addition, the intakes of energy and nutrients were seriously insufficient except niacin. The intakes of dietary fiber, vitamin C, and calcium were as low as 17.2%, 27.3%, and 29.4% of RNI/AI, respectively. The delayed onset of lactation accounted for 28.4% (58/204) and non-delayed ones, 71.6% (146/204). Multivariate unconditional logistic regression showed that primiparity (ORAdjust=5.66) and cesarean delivery (ORAdjust=2.60) were risk factors for the delayed onset of lactation, whereas breastfeed >2 times in the first 24 h and second 24 h (both ORAdjust=0.49) were protective factors for delayed onset of lactation. Conclusion Postpartum women in Guangzhou are at high risk of inadequate intakes of all kinds of food, water, energy and nutrients, and thus should be provided with dietary guidelines during early postpartum period. Primiparas and cesarean are risk factors for delayed onset of lactation, while the early breastfeeding experience within 48 h postpartum is beneficial to reduce the incidence of delayed onset of lactation.