Objective：To investigate the autophagy induced by docetaxel in prostate cancer cell line PC-3 and to explore its possible mechanism. Methods：PC-3 cells cultured in vitro were treated with docetaxel. Proliferation inhibition rate of PC-3 cells was assayed by MTT；ultra-structural cellular changes were observed by transmission electron microscope（TEM）；levels of sequestosome 1/SQSTM1 （P６２） and microtubule-associated protein 1 light chain 3 typeⅡ（LC-3Ⅱ） protein were detected by Immunofluorescence and Western blot，qualitatively and quantitatively；level of mRNA of autophagy gene Beclin-1 was detected by RT-PCR. Results：After docetaxel treatment，proliferation of PC-3 cells was inhibited effectively（F=58.684，P=0.000）. Autophagy could be observed in prostate cancer PC-3 cells treated with 10-6 mol/L docetaxel after 24 h. TEM examination revealed the appearance of autophagosome with double-membrane structure. Immunofluorescence and Western blot showed that expression of LC-3Ⅱ was increased（P=0.002，P=0.000，P=0.000） in PC-3 cells after being treated with docetaxel and expression of P62 was decreased（P=0.003，P=0.000，P=0.000）. RT-PCR showed that levels of mRNA of Beclin-1 were increased by docetaxel（P=0.000，P=0.000，P=0.000）. Conclusion：Docetaxel could inhibit the growth of PC-3 cells and induce the appearance of autophagy in PC-3 cells，and the possible mechanism of autophagy induced by docetaxel is related to the increase of Beclin-1 mRNA.