Abstract: Objective To explore the effect of Hedgehog signaling pathway in breast carcinogenesis. Methods CD44+CD24- cells and non-CD44+CD24-cells were selected from cell suspension in the culture system of a serum-free medium by magnetic activated cell sorting system (MACS), real-time RT-PCR was employed to detect the expression of SHH,PTCH1,SMO and GLI1 mRNA in CD44+CD24- cells and non-CD44+CD24-cells, immunohistochemistry test was applied to study the expressions of SHH,PTCH1,SMO and GLI1 protein in breast cancer. Results CD44+CD24- cells accounted for 8.25% of breast cancer suspension cells and showed the positive expression of ALDH1A1 protein and Oct-4 protein.The expression levels of SHH、PTCH1、SMO、GLI1mRNA in CD44+CD24- cells were higher than those in non-CD44+CD24-cells. SMO and GLI1 expressions were increased in triple-negative breast cancer.Conclusions Hedgehog signaling is activated in breast cancer stem cell CD44+CD24- cells and to stop the recurrence and drug resistance by inhibiting the activation of Hedgehog signaling in breast cancer cells maybe an effective measure.