Background: There was no standard treatment for advanced mucosal melanoma patients. BEAM study have demonstrated the effectivity and safety of bevacizumab combined with carboplatin plus paclitaxel in patients with previously untreated metastatic melanoma. This study was to evaluate the activity of bevacizumab combined with carboplatin plus paclitaxel in Patients with Previously Untreated Advanced Mucosal Melanoma. Methods: This study is an open-label, multicenter, randomized phase II trial. Eligible patients had metastatic, or unresectable mucosal melanoma without any systemic therapy. Additional inclusion criteria included ≥ 1 measurable disease、ECOG PS 0/1, and adequate organ functions. The patient with mutations in c-KIT or BRAF-V600E will be excluded from this study. Patients were randomly allocated in a 1:1 ratio to receive bevacizumab (CPB arm, 5mg/kg every two weeks) or placebo (CP arm) with carboplatin (area under the curve, 5) plus paclitaxel (175 mg/m²), all by intravenous infusion. Treatment was continued for both groups until disease progression, unacceptable toxicity, death, or withdrawal of consent. The primary study endpoint is progress-free survival (PFS). Overall survival, disease control rate, and safety will also be assessed. Results: The first patient visit was December 1, 2013; ninety-four of a planned 182 evaluable pts have been enrolled; 63.8% female, median age was 59 years old, and randomly assigned to the CBP (n = 46) or CP arm (n = 48). The objective response rate was 10.9% and 4.1% respectively. The median progression-free survival was 5.0 months and 3.0 months respectively (p = 0.028). The median overall survival was 12.0 months and 11.5 months respectively (p = 0.754). Treatment emergent grade 3 or 4 adverse events were neutropenia (13.0%), hypertension (4.3%), proteinuria (4.3%) in the PCB arm; and neutropenia (10.4%) in the PC arm. Conclusions: This is the largest study about advanced mucosal melanoma which demonstrated that bevacizumab in combination with carboplatin plus paclitaxel is active and safe as first line therapy in advanced mucosal melanoma. Clinical trial information: NCT02023710