This study aims to enhance the hydrogen (H) production from marine macro algae (Ulva Reticulate) by microwave combined with hydrogen peroxide (HO) under alkaline condition. Microwave (domestic type) (M) pretreatment of algal biomass at its optimal power (40%) resulted in 27.9% COD solubilization at 15 min time interval. When this optimal microwave power was combined with HO (MH) an increment in COD solubilization was achieved at 24 mg HO/g macroalgae dosage. Under alkaline condition (pH 7-12), microwave and HO combination (MHA) yielded better result than MH. At optimal alkaline condition (pH 10), MHA pretreatment shows a COD solubilization of 34%. Microwave in alkaline condition induces decomposition of HO and more OH radical synthesis. This synergistically promotes solubilization. The MHA process considerably diminish time and specific energy required for biomass disintegration. Among the samples, highest H yield of 87.5 mL H/g COD was observed for MHA.