The variations of optical absorption of gold nanoshells with the shell thickness, size of the core, and core dielectric constant have been investigated by means of Mie theory. It was found that with the increase in the thickness of the shell, the strength of absorption peak increases first and then decreases. We also observed that with increasing core size the maximum optical absorption of the particles decreases. Furthermore, the increase of the core dielectric constant reduces the strength of absorption peak and the hollow gold nanoshells have the maximum optical absorption. We ascribe the change of the absorption peaks to the plasmon hybridization and the competition between the variations of conduction and oscillation electrons.