Objective        To investigate the relationship between the alterations of circulating tumor cells (CTC) in peripheral blood and the curative effect of neoadjuvant chemotherapy for breast cancer.        Methods        A total of 70 patients with confirmed lateral breast infiltrating ductal carcinoma without obvious metastasis hospitalized in our department from March 2010to September 2011 were enroll

ed in this study. Venous blood samples of 5 ml were collected from their upper limb of health side before and after 2 to 6 cycles of TE regimen as neoadjuvant chemotherapy (paclitaxel 175 mg/m

2

epirubicin 60 mg/m

2

d

1

21 d/cycle). Density gradient centrifugation was used to enrich mononuclear cells in blood specimens. Fluorescence quantitative RT-PCR was used to detect the mononuclear cells positive to cytokeratin-19 (CK-19).        Results        Before neoadjuvant chemotherapy

24.29% patients (17/70) had CTC detected

which was related with age (

P

=0.008) and HER-2 expression (

P

=0.022). According to the result of having CTC detected or not before and after chemotherapy

the patients were divided into 4 groups

that is

positive to positive

positive to negative

negative to positive and negative to negative groups. When the Response Evaluation Criteria in Solid Tumors (RECIST) criteria was used to evaluate the efficiency of neoadjuvant chemotherapy

it was 66.67% (2/3)

78.57% (11/14)

0 (0/4) and 71.43% (35/49) respectively for the above 4 groups with significant difference（

P

=0.023）. When the efficiency was evaluated by the Miller-Payne grading system

it was 66.67% (2/3)

71.43% (10/14)

0(0/4) and 69.39% (34/49) respectively for the above 4 groups with significant difference（

P

=0.043）.       Conclusion        The alteration of CTC before and after chemotherapy has a certain relationship with efficiency of neoadjuvant chemotherapy. CTC can be regarded as a predictor for evaluating neoadjuvant chemotherapy.