The analysis of bio oils from fast pyrolysis of sawdust and rice husks in Korea was performed in a bubbling fluidized bed pyrolyzer (0.2 m I.D. ×2 m high). The bubbling fluidized bed pyrolyzer is consisted of air compressor, gas flow meters, pre-heater, fluidized bed reactor, screw feeder, cyclone, multiple heat exchanger and electrostatic presipitator. Multiple heat exchanger and electrostatic precipitator were equipped at the exit of cyclone to capture oil mist. The effect of operation conditions, such as reaction temperature, solid feeding rate, oxygen ratio and so on, on the composition and yield of bio oil have been investigated. The bio oil is mainly composed of carbohydrates, guaiacols, phenols, syringols, and furans. As the reaction temperature increases, the peak intensity of high molecular compounds decreases in composition to low molecular compounds such as phenol.