Super purity silica glass was synthesized by Plasma Chemical Vapor Deposition (PCVD) method, during which inductively coupled plasma was used as the heat source. Influence of structure factor of tube and working gas on output power were discussed. The structure factor of tube was confirmed by analyzing the relation between structure factor of tube and coupling efficiency. With the increase of coupling efficiency, output power and plasma radius grow bigger. Super purity silica glass can be successfully synthesized when air was used working gas, during which input power was 100kW and output power reached to 40kW.