Abstract：Objective：To observe the application effect of apparent diffusion coefficient(ADC) value of diffusion-weighted imaging(DWI) of magnetic resonance(MR) in evaluating the early curative effect of neoadjuvant chemotherapy(NAC) for triplenegative breast cancer of the liver depression and congealing phlegm type. Methods： A total of 32 cases of patients with locally advanced triple- negative breast cancer of the liver depression and congealing phlegm type were selected. Magentic resonance imaging(MRI) was performed before NAC and after two- cycle chemotherapy. The minimum ADC value of the lesion was recorded and the ADC change rate(ΔADC) was calculated. According to the clinical effect all patients were divided into the complete remission(CR) + partial remission(PR) group， the disease stability(SD) + disease progression(PD) group. Accordin to the pathological effect，all patients were divided into the pathological complete remission(pCR) group and nonpathological complete remission(non- pCR) group. The correlations between changes in ADC values and ΔADC and the evaluating results of curative effect were compared between the two groups respectively. Results： According to the evaluation of NAC clinical effect，among 32 patients，there were 20 cases in the CR+PR group and 12 cases in the SD+PD group. A total of 28 patients underwent modified radical mastectomy and four cases underwent breast- conserving surgery. According to the grading of postoperative pathological reactions，there were 18 cases in the pCR group and 14 cases in the non-pCR group. Before NAC，there was no significance in differences being found in the comparison of minimum ADC value of the lesion between the two groups(P＞0.05). After two- cycle NAC， ADC value and ΔADC in the CR + PR group were increased when compared with those in the SD+PD group，the difference being significant(P＜0.05)；ADC value and ΔADC in the pCR group were increased when compared with those in the non-pCR group，the difference being significant(P＜0.05). Conclusion： After two cycles of NAC treatment for triple- negative breast cancer of the liver depression and congealing phlegm type，the minimum ADC value of the lesion has a good evaluation value for its early curative effect.