Objective: To explored whether BMI is associated with adverse events after shoulder arthroplasty. Methods: The authors searched PubMed, EMBASE, web of science and Cochrane in English and Wanfang, CNKI and VIP in Chinese for the relationship between obesity and shoulder replacement. The quality of the literatures was evaluated by Newcastle Ottawa scale (NOS), and the data of the included literatures were extracted. Revman5.3 software provided by Cochrane Collaboration Network was used for meta-analysis. Results: Finally, 10 literatures were included, and the sample size of each study ranged from 76 to 144139. All the studies included were observational studies, including 3 prospective studies and 7 retrospective studies, which were all high-quality studies. Meta-analysis showed that the postoperative infection rate of obese patients (BMI>30kg/m2) was higher [OR=3.83, 95%CI(2.72-5.41), I2=64%, and the incidence of VTE was also higher [OR=3.93, 95%CI(3.61-4.29)]. The operation time of overweight patients (BMI>25kg/m2) was longer [MD=6.90, 95%CI(3.79-10.00), I2=0%]. There were no significant differences in postoperative complications of overweight patients and normal weight patients [OR=0.87, 95%CI(0.71-1.08), I2=38%, postoperative revision rates of obese and non-obese patients [OR=1.48, 95%CI(1.39-1.57), I2=71%, hospitalization time [MD=0.03, 95%CI(-0.03-0.09), I2=1%] and American Shoulder and elbow surfaces (ASE) scores were not significantly different [MD=0.36, 95%CI(-7.38-8.11), I2=0%]. Conclusion: The infection rate of obese patients after shoulder replacement is higher, and the operation time of overweight patients is longer, but in general, all patients can get good functional results, and shoulder replacement is beneficial to patients.