Human milk exosomes were obtained by the ultracentrifugation method and they were identified with particle size， morphology and biomarker proteins. The expestion of microRNA (miRNA) in human milk exosomes of different lactation periods wereobtained by high throughput sequencing technology. This study found that total 852 miRNA were detected in human milk exosomes and there were 283 miRNA expressed stably during the three periods after analyzing the profile of miRNAs. Among them， the top ten miRNA accounted for more than 50% of the total .The expression of high-expressed miRNA (accounted for more than 2% of the total) had no significantly changed during three lactation periods， while the expression of low-expressed miRNA(accounted for less than 0.01% of the total) were significantly changed in different lactation. In addition， there were 88 inflammation- related miRNA in human milk exosome， in which 65 miRNA were stable during different lactation periods. This study suggested that maybe human milk exosomes could regulate inflammation and provided a basis for better understanding the physiological functions of human milk exosomes in different lactation period.