Objective: To investigate the influence of paclitaxel on expression of autophagy-associated protein LC3 in triple negative breast cancer (TNBC) cells and the significance. Methods: The inhibitory effect of paclitaxel on proliferation of TNBC MDA-MB-231 cells was determined by CCK-8 assay and then the 25% inhibition concentration (IC25) value was calculated. In MDA-MB-231 cells after treatment with IC25 concentration of paclitaxel, the expressions of LC3 protein and apoptosis-associated proteins as well as the cell apoptosis rates were determined by immunofluorescence histochemistry, Western blot analysis and flow cytometry, respectively. Results: The proliferation effect of TNBC-MDA-MB-231 cells was significantly inhibited by paclitaxel in a concentration-dependent manner (P<0.05), with an IC25 value of 3.11 μg/mL. In MDA-MB-231 cells after treatment with 3.11 μg/mL paclitaxel, the expression level of LC3 protein as well as LC3B/LC3A ratio were significantly increased, the expression levels of the apoptosis-related protein Bax and caspase-3 were significantly decreased, and the total and early apoptosis rates were significantly decreased (all P<0.05). Conclusion: Paclitaxel can induce the increased expression of the autophagy-related protein LC3, and this action may probably reduce the cell apoptosis and thereby cause paclitaxel resistance in TNBC cells.