To systematically review and meta-analyze all published studies, written in Chinese and published in China, focusing on mindfulness-based interventions for Chinese breast cancer patients’ mental health and quality of life outcomes.Following the Cochrane guideline, this study searched across five electronic debases, two professional websites, two major Chinese oncology journals, and reference lists of existing reviews and included studies. Meta-analysis was conducted using meta-regression with robust variance estimation. Publication bias and risk of bias were assessed and evaluated in the final analysis.A final of 35 clinical trials included 126 effect sizes and 3,100 participants. Studies reported an overall large and statistically significant treatment effect, g = 0.963, p < .001.Mindfulness-based interventions were significantly effective for Chinese breast cancer patients and are recommended for oncology social workers. Moderator analyses identified group-based mindfulness interventions as significantly more effective than individual-based interventions, and mindfulness-based interventions delivered as therapeutic treatment were significantly more effective than ones delivered as supportive treatment.