Objective: Different surgical methods have different risks and benefits. The Chinese breast cancer(BC) patients’ decision-making of surgical treatment become a critical research question. Patients are often offered several options before surgery, and decision preparation play an important role in decision process. However some patients regret the original decision afterward. To understand the current situation, this study explore mainly explores the status of decision regret among newly diagnosed BC patients,and tests the relationship between decision conflicts, decision-making preparation, and decision regrets. Methods: A cross-sectional survey was conducted. Totally 320 postoperative BC patients were studied using a self-made general data scale, Decision Regret Scale, Decision Conflict Scale, and Preparation for Decision Making Scale. Basic descriptive analyses, Pearson’s correlation analyses and regression analyses were performed. Results: The average score of decision regret among BC patients after surgery was 34.28. Decision regret was positively associated with decision conflict (r=0.853, p<0.01), and negatively associated decision preparation (r=-0.404, p<0.01). Decision-making preparation plays a regulatory role for the emergence of decision conflicts and regrets. The correlation between decision conflicts and decision regrets increases with the increase of decision-making preparation. Conclusion: The adverse effects of decision conflicts on decision regrets gradually increase with the increase of decision-making preparation. Results indicate that reducing decision preparation can be expected to improve the level of decision regret among Chinese BC patients.Thus, Clinical staffs should encourage patients to actively participate in decision-making, provide specialized information support, and improve the level of decision regret among Chinese BCpatients after surgery.