Objective:This study focused on the analysis and evaluation of the differences in the chemical composition of onions from different origins. Methods:Onions from two main production areas in North and South China (Yunnan and Heilongjiang) were used as raw materials, and the differences in chemical composition content and characteristic chemical composition prostaglandin A1 between the two production areas were analyzed by ultra-high performance liquid chromatography (UHPLC) combined with multivariate statistics. Results:A total of 73 peaks were identified by UHPLC, and the chemical contents of onions from two origins could be distinguished by orthogonal partial least square discriminant analysis (OPLS-DA), combined with VIP values ＞ 1,P＜ 0.05 and S-plot. 0.05 and Splot analysis, and a total of 11 major markers of variation were screened. The PGA1 content of Yunnan onion \[(197.21±63.22) mg/kg\] was significantly higher than that of Heilongjiang onion \[(121.37±43.12) mg/kg\]. Conclusion:There were significant differences in the chemical composition content and PGA1 content of onion between the two origins in Yunnan and Heilongjiang.