This work deals with the gasification of the biomass char in a fixed bed gasifier and ultimately the production of syngas. Gasification of biomass is an endothermal process of thermal conversion that transforms solid fuel into gas. A limited supply of air serves as the oxidizing agent. The resultant gas consists of Carbon dioxide and monoxide, hydrogen, methane; minimal quantities of higher levels of hydrocarbons, nitrogen, oxygen, contaminating agents, including small chips, tars, ash etc. The hydrogen gas thus produced is a future fuel since this is a renewable energy source and acts as an alternative fuel. The syngas produced has many applications in the present scenario. The biomass air-steam gasification properties in a fluidized bed have been investigated in this paper. A number of experiments were conducted to study the effects on gas composition, gas emission, vapor decomposition and low heating (LHV) from reactor temperature, vapor to biomass ratio (S / B) and biomass particle size. The fuel gas production ranged from 1.43 to 2.57 Nm3/kg of biomass and the LHV of the fuel gas between 170.1 and 7772.95 kJ/Nm3. The results show that hydrogen production was driven by a higher temperature. A smaller particle has also been shown to be more favorable for higher LHV gas and yields.