Objective To observe the clinical results of combination therapy for multiple myeloma by arsenic trioxide,melphalan,vitamin C and dexamethasone.Methods 18 cases with multiple myeloma,12 males and 6 females were given the treatment including arsenic trioxide,melphalan,vitamin C and dexamethasone combination therapy;the dosage of arsenic trioxide 10 mg,d1~5,d8~12;vitamin C 1.0 g,d1~5,d8~12;dexamethasone 20 mg,d1~4,d8~11;melphalan 2 mg,tid,d1~12.Complete response(CR),partial response(PR),minimal response(MR),no ehange(NC)were observed.Results The CR werel6.7%(3/18),PR were 77.7%(14/t8),MR were 5.6%(1/18).Conclusion Combinational arsenic trioxide,melphalan,vitamin C and dexamethasone is an effective therapy with less side effects,which can be considered for treating the initial or relapsed or refractory MM.