Background: Efficacy of L-asparaginase-based regimens has been confirmed for patients with extranodal natural killer/T-cell lymphoma (ENKTL). However, targeted therapy and optimal chemotherapy regimens for ENKTL remain to be determined. As high levels of vascular endothelial growth factor A (VEGF) is associated with a poor prognosis in ENKTL, we evaluated the efficacy and safety for bevacizumab (BEV) in the combination with gemcitabine, PEG-asparaginase, oxaliplatin and dexamethasone (BEV-GemAOD) regimen in untreated ENKTL in the Phase II Study (NCT 01921790). Methods: Patients with newly diagnosed ENKTL in stageⅠ-Ⅳ from 18 to 80 years were eligible for enrollment. BEV-GemAOD regimen (bevacizumab 7.5 mg/kg d1; gemcitabine 1000 mg/m² d1, d8; PEG-aspargase 2500 U/m² d1; oxaliplatin 130 mg/ m² d1; dexamethasone 20 mg, d1-3; q3w) was planned as the protocol treatment. Patients with stage I/II received sandwich chemoradiation (BEV-GemAOD×3 cycles followed by RT 50.4 Gy followed by BEV-GemAOD×3 cycles). For stage III/IV, BEV-GemAOD regimen was repeated for six cycles. The primary endpoint was overall response rate (ORR) after six cycles of BEV-GemAOD. Secondary endpoints were progression-free survival (PFS), overall survival (OS), and toxicity. Results: 56 patients were enrolled from Oct 2013 to Feb 2018. 43 patients were evaluable for response: the median age, 37 years (range: 18-65 years); female, 25.6%; ECOG PS > 1, 20.9%; stageⅣ, 37.2%; elevated LDH, 39.5%; elevated EBV DNA, 60.5%. After 2 cycles of BEV-GemAOD, ORR were 100%. CR rate (CRR) in stage Ⅰ/Ⅱ and Ⅲ/Ⅳ were 88.9% (24/27) and 25% (4/16), respectively. After 6 cycles ORR were still 100%. CRR increased to 100% (27/27) and 87.5% (14/16), respectively. At median follow-up of 25.3 months, 2-year PFS and OS were 83.3% and 78.8%. The most common hematologic adverse event of grade 3/4 was neutropenia (32.6%). No patient died of treatment related toxicity. Conclusions: These results demonstrate that BEV-GemAOD regimen is feasible and provides high ORR, CRR and survival for either early- or late-stage patients with newly diagnosed ENKTL. Clinical trial information: NCT01921790