Pilot scale of oxygen blown high temperature gasification process using waste plastic has been studied. 0.5 ton/day of pilot scale gasification system was built, and successfully demonstrated to be operated without consumption of auxiliary fuel while preventing slag clogging. The effect of oxygen flow rate on gas composition, gas yield, and soot yield was investigated. The change of oxygen flow rate affected the change of gas composition, however hardly affect the molar ratio of [H₂]/[CO], which showed stable value at 0.6. Gas yield and cold gas efficiency showed maximum value at 0.9 of the mass ratio of oxygen to waste (O₂/waste ratio), which was 1.3 Nm³/kg-fuel and 57%, respectively. Meanwhile, carbon conversion showed maximum value of 94.2% at 1.3 of the O₂/waste ratio. The syngas from the gasification process, power generation using gas engine was successfully demonstrated.