OBJECTIVE To explore the effect of Bushen Yanggu Decoction (BYD) on drug resistance and proliferation of human multiple myeloma-resistant KM3/BTZ cells. METHODS Human multidrug-resistant KM3/BTZ cells were established by Bortezomib (BTZ) gradient induction. The effects of commonly used chemotherapeutic drugs and serum containing Bushen Yanggu Decoction (BYD) on the proliferation of KM3 cells and KM3/BTZ cells were detected by MTT assay. RT-qPCR and Western blot were used to detect the expression of Par-4, HSP27 and P-gp genes. Flow cytometry was used to detect cell apoptosis. RESULTS The established KM3/BTZ cells could produce varying degree of resistance to commonly used chemotherapeutic drugs. Among them, the highest resistance index (RI) to BTZ was 20.269. MTT assay showed that the proliferation of KM3/BTZ cells treated with serum containing Bushen Yanggu Decoction was inhibited, and the inhibitory effect increased with the serum concentration incranse of Bushen Yanggu Decoction. The serum containing Bushen Yanggu Decoction could inhibit the proliferation of KM3/BTZ cells, and induce apoptosis, significantly reduce the drug-resistance of KM3/BTZ cells, up-regulate the expression of Par-4, down-regulate the expression of HSP27 and P-gp. CONCLUSIONS Bushen Yanggu Decoction can effectively inhibit the proliferation of KM3/BTZ cells and induce apoptosis. Bushen Yanggu Decoction can effectively reverse the multidrug-resistance of KM3/BTZ cells. The mechanism may be related with the decrease of expression of HSP27 and P-gp and the increase of expression of Par-4.