DC self bias is the important process reading of high density RF plasma source etching process, by which ion energy and wafer bombardment are decided. In this research, ICP etcher is used and the effects of plasma power,platen power,etcher chamber pressure and HBr gas flow on the DC self bias are studied by using HBr as the etching gas. The result shows that the higher DC self bias is achieved when elevating either platen power or reactor pressure and the lower DC self bias is gotten while plasma power is increased. The effect of HBr gas flow and etched wafer materials on the DC self bias are not seen obviously in this process regime.