We aimed to investigate the differences in efficacy and safety between bevacizumab combined with capecitabine maintenance therapy and capecitabine monotherapy for RAS-mutant mCRC （as defined by mutations in KRAS and NRAS exons 2-4）controlled by bevacizumab plus FOLFIRI chemotherapy for at least 12 weeks. ll patients were first treated with bevacizumab combined with FOLFIRI for at least 12 weeks of induction therapy. 78 patients were in the observation group (bevacizumab plus capecitabine) and 76 patients were in the control group (capecitabine alone). The median progression-free survival (mPFS)of patients was 9.0 months (95% CI 8.0-10.0) in the observation group and 7.2 months (95% CI 6.0-8.4) in the control group, with a statistically significant difference (p < 0.05). Bevacizumab combined with capecitabine was well tolerated and contributed to a longer PFS time than capecitabine alone...