The influence of the dissolution process of γ'' phase on the subsequent precipitating process of γ'' phase was investigated and the effect of Al+Ti contents and Ti/Al ratios to γ'' precipitate was also simulated. The precipitation of γ'' phase are influenced by the dissolution of γ'' phase and the diffusion of Al and Ti content. The size of γ'' precipitate decreases with the increase of solution time and temperature. The precipitation of γ'' phase exhibits various sizes, shapes and distributions under the water cooling condition. It can be shown in TTT and CCT curves that the precipitating temperature increases and the precipitating time decreases under various cooling rates with changes in Al+Ti contents. The precipitation of γ'' phase can not inhibited under the water cooling condition and even when the cooling rate is 1000 ℃/min. Meanwhile, no obvious influence is observed on the precipitation process of γ'' phase with the various Ti/Al ratios.