Abstract: Objective To study the clinical value of serum homocysteine（Hcy）， carbohydrate chain antigen 15-3（CA15-3）and folic acid（FA）in breast cancer patients before and after operation or with recurrence and metastasis. Methods From January 2010 to December 2010，387 patients with primary breast cancer who underwent surgery in our hospital were enrolled in this study. The serum levels of Hcy，CA15-3 and FA in breast cancer patients before and after operation were compared. According to the 5-year follow-up data， the patients were then divided into recurrence group（47 cases） and non-recurrence group（340 cases）. The serum levels of Hcy，CA15-3 and FA between both groups were compared. The relationship between FA，CA15-3 and Hcy were analyzed. Results The postoperative serum Hcy and CA15-3 levels were（11.83±4.25） μmol/L and（13.02±3.01） U/ml， both lower than（17.27±6.82） μmol/L and（37.29±15.92）U/ml preoperative，and the postoperative serum FA level was（7.84±3.17） ng/ml， higher than（5.16±2.37） ng/ml with statistical significance（P<0.05）. In recurrence group， postoperative serum Hcy and CA15-3 levels were（16.08±5.93） μmol/L and（28.41±13.85） U/ml， both higher than（11.92±4.31） μmol/L and（14.25±2.96） U/ml of nonrecurrence group， and the postoperative serum FA level was（5.12±2.21） ng/ml， lower than（7.85±3.09） ng/ml of nonrecurrence group with statistical significance（P<0.05）. The abnormal rates of serum Hcy， CA15-3 and FA in recurrence group were higher than those of nonrecurrence group（P<0.05）. As for breast cancer patients with recurrence and metastasis， the abnormal rates of Hcy， CA15-3 and FA in clinical stage III and IV were higher than those of clinical stage I and II period（P<0.05）. The level of FA in patients with breast cancer was negatively correlated with Hcy and CA15-3（r=-0.286 and -0.346， P<0.05）， and Hcy level was positively correlated with CA15-3（r=0.402， P<0.05）. Conclusion The serum CA15-3 and FA levels in patients with recurrent and metastatic breast cancer were higher，and the Hcy level was lower，which can be used to predict the recurrence and metastasis of breast cancer patients.