Objective: The aim of this study was to assess the long-term effect of breast conservation with breast intensity-modulated radiotherapy (IMRT) for early-stage breast cancers. Methods: Pub Med, EMBASE, Cochrane Library, Chinese Biomedical Literature Database were searched to identify relevant original published trails, and the references of eligible studies were manually screened. Randomized controlled trails reported in any language, comparing breast IMRT with conventional radiotherapy (RT) in patients with early-stage breast cancer were eligible for inclusion. Two investigators independently assessed the quality of included trials and extracted data. The RevMan 5.0 software was used for statistical analysis. Results: Four trials involving 1440 patients were included. The results showed that in the IMRT group, the occurrence of acute moist dermatitis, the edema of the mammary gland and the occurrence of hyperpigmentation were lower than those of RT group, the pooled risk ratio value and 95% confidence interval were 0.28 (0.17-0.48), 0.03 (0.00-0.21) and 0.06 (0.02-0.15) respectively. The use of IMRT did not correlate with pain and quality of life, but the presence of moist desquamation did significantly correlate with pain and reduced quality of life. Conclusion: The currently available evidence showed that IMRT significantly reduces the occurrence of moist acute dermatitis anywhere in the breast and alleviates the suffering of patients and improves the quality of life of patients. Future large-scale, high-quality, double-blind trials are needed.