Abstract: Objective：To observe the efficacy and safety of two PAD regimens with different doses of bortezomib (bortezomib + Epirubicin + dexamethasone) in the treatment of patients with multiple myeloma (MM). Methods：The clinical data of 32 MM patients treated with PAD regimens were retrospectively analyzed. The doses of intravenous bortezomib were different in two PAD regimens. Patients in group PAD 1 (n=20) received bortezomib 1.3 mg/m2 through intravenous injection on d 1, d 4, d 8, and d 11, epirubicin 20 mg through intravenous infusion on d 1 to d 4, and dexamethasone 20 mg through intravenous infusion d 1 to d 4, and d 8 to d 11. Patients in group PAD 2 (n=12) received bortezomib 1.6 mg/m2 through intravenous injection on d 1, d 8, and d 15, epirubicin 20 mg through intravenous infusion on d 1, d 8, and d 15, and dexamethasone 20 mg through intravenous infusion on d 12, d 89, and d 1516. All patients received 3 to 6 courses of treatment and each course lasted for 28 days. Clinical efficacy and adverse reactions of two groups of MM patients were compared after the completion of 3 courses. Results：After the first three courses, the effective rate of group PAD 1 was 80.0%, the effective rate of group PAD 2 was 83.3%, and there was no significant difference between the two groups. There were more herpes zoster patients in group PAD 1 than group PAD 2 (30% vs 0%), and the difference was statistically significant (P<0.05). There were no statistical differences in the incidence of gastrointestinal reaction, peripheral neuritis, granulocytopenia, and thrombocytopenia between the two groups (20.0% vs 16.7%, 25.0% vs 16.7%, 15.0% vs 16.0%, and 10.0% vs 8.0%, P>0.05). Conclusions：The PAD regimen with intravenous injection of bortezomib 1.6 mg/m2 once a week is similar to the PAD regimen with intravenous injection of bortezomib 1.3 mg/m2 twice a week in efficacy, but it is safer with less adverse reactions.