Abstract: Objective To investigate the effect of Jinlong Capsules on reversing paclitaxel-resistance,vincristineresistance and enhancing sensitivity in human cancer cell lines. Methods MTT assay was adopted to test cytotoxicity, sensitization and MDR reversing of Jinlong Capsules in paclitaxel-resistant lung adenocarcinoma cell line, paclitaxel-resistant breast cancer cell line, vincristine-resistant squamous carcinoma cell line, fluorouracil-resistant hepatocarcinoma cell line and the parent cells. Reversal fold was calculated from median inhibitory concentration (IC50). Results Jinlong Capsules showed no obvious selectivity among these different cell lines, and IC50 was kept at 1.5 ~5.2 mg/ml. In paclitaxel-resistant lung adenocarcinoma cell line, Jinlong Capsules reversed the acquired drug-resistance at a dosage of 100, 200 and 400 μg/ml, with a reversal fold of 2.25, 2.99 and 10.64. In paclitaxel-resistant breast cancer cell line, Jinlong Capsules enhanced its sensitivity at a dosage of 50, 100 and 200 μg/ml, and the highest sensitization fold reached up to 12.61. In fluorouracil-resistant hepatocarcinoma cell line, Jinlong Capsules enhanced its sensitivity at a dosage of 200 μg/ml, with a fold change of 4.03. Conclusion Jinlong Capsules could reverse MDR and enhance the sensitivity in drug-resistant human tumor cells in a certain extent, accompanied with a selectivity in cell lines and chemotherapy drugs.