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Biomass energy is a clean renewable energy and has gained great attention as an alternate source of energy in the world. The consumption of fossil fuels has been increasing with the growth of population and causes the depletion of these resources as well as environmental threat. Ultimately, the production of sustainable energy has turned out to be the concern of today and its consumption has been increasing. In the developing countries, the production of biomass energy is 35% whereas in the developed countries, it is about 14%. Fluidized bed fast pyrolysis is one of the most promising technologies among the thermochemical conversion processes to convert waste biomass into liquid fuels due to high biomass conversion efficiency. Pakistan is an agricultural based country and produces agricultural wastes such as wheat straw, rice straw, cotton stalks, maize stalks, sugar cane trash, corn stover, tobacco stalks etc in huge volume. The annual production of these residues is about 84 million tons and conventional use of this waste is for the purpose of heating, cooking and animal fodder. This agricultural waste is an alternate potential resource for energy production and its exploitation into liquid fuel using different technologies should be considered. Consequently, the agricultural wastes which are useless and produce environmental problems can be made into more valuable energy rich products which are environment friendly.Fast pyrolysis is the thermal decomposition of biomass in the absence of oxygen at moderate temperature and high heating rate. It is used to convert the waste biomass into liquid fuel with the advantage of storage and transportation over the combustion and gasification processes. Fast pyrolysis experiments are carried out in a bench scale fluidized bed reactor (dia: 100 mm, height: 700 mm) using maize stalks as feedstock shown in fig1. Operating parameters for the investigation are set as: temperature 350-500°C, feed rate 400-1000 g/h, particle size < 2mm, gas flow rate of nitrogen 2-3 m3/h and moisture content of feed <10 wt %. Chemical composition of bio oil produced from the pyrolysis of maize stalks is determined by GC-MS and FTIR analysis whereas co-products such as uncondensable gas is characterized using GC analyzer and char by bomb calorimeter. The maximum bio oil yield is 32 wt% at the optimum temperature of 450°C.