Abstract: Inert gas has great effect on reducing the liquid metal incipient boiling superheat. By taking into account the inert gas volume variation in the wall cavities and inert gas diffusion, the local parameter variations during pool boiling nucleation process were analyzed and the effects of different parameters on liquid metal incipient boiling superheat with inert gas effect were studied. The results show that inert gas could cause complex second-grade effect. For accurate analysis of parameter effects like heat flux and pressure, the detail consideration of inert gas effect during nucleation process is necessary.