Objective:To examine the efficacy and safety of bathing therapy with Taohong Siwu Decoction (桃红四物汤,TSD) in the treatment of early-stage,mild-moderate diffuse cutaneous systemic sclerosis (dcSSc).Methods:This randomized,placebo-controlled trial enrolled 148 men and women (18-60 years) with dcSSc (disease duration ≤12 months) and baseline modified Rodnan skin score (MRSS) ≥10.Patients were randomized into a TSD group (71 cases bathing with TSD plus oral prednisone) or control group (71 cases bathing with placebo plus oral prednisone).Bathing (40℃, 30 min) of the upper and lower limbs was carried out once daily for 12 consecutive weeks.The primary outcome measure was MRSS;secondary outcomes were Raynaud\'s phenomenon (RP) score,quality of life (QOL),physician visual analogue scale (VAS),patient VAS,percent predicted diffusing capacity for carbon monoxide (DLCO),percent predicted forced vital capacity (FVC),erythrocyte sedimentation rate (ESR),C-reactive protein (CRP) level and overall treatment effect.Results:The final analysis included 135 patients (control group,68 cases;TSD group,67 cases).Primary and secondary outcome measures after 2 weeks of treatment showed no improvement (versus baseline) in both groups,with no differences between groups.At 12 weeks,QOL,physician VAS,patient VAS,ESR and CRP were improved in both groups,but MRSS and RP score were improved only in the TSD group (all P＜0.05).MRSS,RP score,QOL,physician VAS,patient VAS,ESR and CRP differed significantly between groups (all P＜0.05).Meanwhile,the overall treatment effect was significantly higher in the TSD group than in the control group (P＜0.05).Adverse events in the two groups were similar (P＞0.05).Conclusions:Bathing with TSD plus oral prednisone achieves better outcomes than oral prednisone alone in patients with dcSSc and is not associated with serious adverse events.