Objective To analyze the expression levels of IL-11 and connective tissue growth factor (CTGF) in patients with breast cancer and their correlation with bone metastasis .Methods The 108 cases of breast cancer(breast cancer group) ,30 cases of breast benign tumor (breast benign tumor group) and 30 cases of healthy controls (control group) were performed by ELISA to de-tect the expression of serum IL-11 ,CTGF ,and their relationship with bone metastases was analyzed .All the patients were followed up for 2 years ,survival rates between different expression levels of IL-11 ,CTGF were compared .Results Compared with those in control group and breast benign tumor group ,the expressions of IL-11 ,CTGF in breast cancer group were increased (P<0 .05) , while there was no significant difference between control group and breast benign tumor group (P<0 .05) .The levels of serum IL-11 ,CTGF in different stages of breast cancer with bone metastases were significantly higher than those in breast cancer without bone metastases(P<0 .05) ,and the levels of IL-11 ,CTGF in bone metastases stage of Ⅲ - Ⅳ were higher than those in bone me-tastases stage ofⅠ - Ⅱ(P<0 .05) .Serum IL-11 and CTGF was positively correlated in breast cancer patients with or without bone metastases(r=0 .514 ,0 .477 ,P<0 .05) .At 2 year after surgery ,the survival rate in patients with high expression of IL-11 and CT-GF was significantly lower than that with low expression (χ2 =4 .50 ,5 .18 ,P<0 .05) .Conclusion The levels of serum IL-11 ,CT-GF in breast cancer patients are overexpressed ,which could be used as an effective serological tumor markers for diagnosis of bone metastases and assessment of prognosis .