Objective To investigate the changes of nutrients in colostrum, transitional milk, mature milk and late milk after storage at indoor temperature for 3 h, at 4 ℃ for 24 h, at -18 ℃ for 30 d, and at -18 ℃ for 90 d, so as to select the most suitable storage method of milk. Methods Fifteen pregnant women registered in the Shanghai Hongkou Liangcheng Village Street Community Health Service Center, who were expected to give birth from January to June in 2019, were selected. The breast milk of each woman was followed from delivery to 10 months after breast-feeding. Colostrum, transitional milk, mature milk and late milk were sampled, and each sample was divided into 5 parts. Changes in protein, fat, lactose, minerals, carbohydrates, vitamins and bacterial colony number of breast milk were detected according to 0 h(16-18 ℃), 3 h (16-18 ℃), 24 h (4 ℃) to 37 ℃, 30 d (-18 ℃) to 37 ℃ after thawing at 40 ℃ and 90 d (-18 ℃) to 37 ℃ after thawing at 40 ℃. Results The results showed that the nutritional components of milk in different stages decreased with time. However, there was no significant difference in the decline of nutritional components in different stages of milk after the same duration of time ( P >0.05). Conclusion The milk at each stage can be stored, and the lactating mother can store the excess milk at any stage as she wishes.