Abstract： objective： To investigate the effect and mechanism of Herba Taraxaci extract on apoptosis， migration and invasion of colorectal cancer cells by regulating the expression of deleted in pancreatic carcinoma locus 4(DPC4). Methods： After treating HT-29 cells with Herba Taraxaci extract of different final concentrations including 1.5，3.0，7.5 and 15.0 mg/mL for 48 hours，cell apoptosis was detected by flow cytometry，the ability of migration and invasion of cells was detected by Transwell method，and expression of DPC4 protein was detected by Western blot. PcDNA3.1- DPC4 was transfected into HT-29 cells，and the effect of over-expression of DPC4 on apoptosis，migration and invasion of HT-29 cells was observed. Si-DPC4 was transfected into HT-29 cells，and the effect of the inhibition of DPC4 expression on apoptosis，migration and invasion of HT-29 cells was observed after being treated with Herba Taraxaci extract. Results：Herba Taraxaci extract in vitro could induce the apoptosis of HT-29 cells and inhibit the migration and invasion of HT-29 cells in an obvious concentrationdependent manner. Fifteen mg/mL of Herba Taraxaci extract can promote the expression of DPC4 protein. Over-expression of DPC4 could significantly promote the apoptosis of HT- 29 cells and inhibit the migration and invasion of HT- 29 cells. Inhibition of DPC4 expression could reverse the effect of Herba Taraxaci extract on apoptosis，migration and invasion of HT- 29 cells. Conclusion： By up- regulating the expression of DPC4， Herba Taraxaci extract can promote the apoptosis of colorectal cancer cells and inhibit the ability of migration and invasion of cells.