Objective To investigate the efficacy and safety of PAD regimen in previously untreated patients with multiple myeloma(MM). Methods We retrospectively analyzed 54 patients with newly-diagnosed MM,who were treated with PAD regimen: Bortezomib 1.3mg/m² subcutaneously on day 1,4,8,11. Liposomal doxorubicin 25～30 mg/m² intravenously on the first day. Dexamethasone 40 mg/d intravenously or orally on days 1～4. Treatment was repeated every 21 days. Response was evaluated according to the International Uniform Response Criteria for MM.Adverse events were graded according to the National Cancer Institute Common Toxicity Criteria,version 3.0. Results ①Overall response:after median 4(2～8) courses of PAD,47patients(87.0%)responsed,including complete response (CR) in 20 (37.0%),very good partial response (VGPR) in 19 (35.2%),partial response (PR) in 8 (14.9%),stable disease (SD) in 5 (9.3%) and progressive disease (PD) in 2 (3.7%). ②Subgroups efficacy: among the 54 patients,35 patients received more than 4 therapeutic courses,and 19 patients received less than 4 courses.The ORR was 97.1% (34/35) and 68.4% (13/19) respectively (P=0.003). Subgroups efficacy were compared according to age,renal function,number of bone destruction,proportion of bone marrow plasma cells,ALB,LDH,β2-MG,cytogenetics,ISS staging and clinical classification. The results indicated that there was no statistical difference(P>0.05). ③Overall safety: adverse events included neutropenia in 8 (14.8%),thrombocytopenia in 8 (14.8%),peripheral neuropathy in 16 (29.6%),diarrhea in 2 (3.7%),constipation in 2 (3.7%),herpes zoster in 4 (7.4%) and bacterial infection in 5 (9.3%). The adverse events relieved or disappeared after symptomatic treatment. ④Subgroups safety: compared by age and courses of treatment,the incidence of overall adverse events and grade 3/4 adverse events in patients older than 60 years and ones younger than 60 were 47.4% vs 60.0% and 15.8% vs 20.1% respectively,(P=0.404,P=1.00). The incidence of overall adverse events and grade 3/4 adverse events in patients with more than 4 therapeutic courses and ones with less than 4 courses were 57.9% vs 54.3% and 21.2% vs 17.1% respectively,(P=1.00和P=0.728). Conclusion PAD regimen has really curative effect in treating patients with newly diagnosed MM. There is a correlation between remission rate and therapeutic courses. It can be used as the first selected protocol for the induction therapy of MM. Its efficacy is independent of traditional prognostic factors.Liposomal doxorubicin has almost no cardiotoxicity. Replacing traditional anthracycline doxorubicin,the adverse events are controllable and the tolerance is generally well. PAD regimen is more proper to be applied to older patients with MM.