Typical grade 654SMo and C-276 were selected to investigate the precipitated phases of high Mo super austenictic stainless steel and Ni-Cr-Mo Nickel-base alloy. Microstructure observation, EDS and phase analysis was taken for 654SMo and C-276 samples at different aging conditions.The results showed that the types and morphology of the precipitated phase in 654SMo and C-276 were different due to their different alloy system athough they both contained high content of Cr, Mo element. About eight kinds of second phases were precipitated in 654SMo, which included σ phase,Cr₂N,μ phase,χphase,Laves phase,M₂₃C₆,M₆C and M₃C. σ phase and Cr₂N were the main harmful phases of 654SMo and the peak precipitating temperature is 900℃. For C-276 alloy, M₆C and μ phase were the main precipitated phases and σ phase wasn’t found under the aging condition of this aticle.