Abstract: The precipitation behaviors of γ′ phases and distribution coefficients of Ni, Al and W between γ and γ′ phases in the Co-Ni-Al-W-Cr alloy were studied by thermodynamic analysis method. The effect of distribution coefficient of Ni between γ and γ′ phases on the alloy strengthening was also discussed. The results show that the stability of the γ′ phase can be enhanced by the addition of Ni. The homogeneity range of the γ′ phase can be enlarged with the increasing of Ni content, which shows that Ni can improve the working temperature of the Co-Al-W-based superalloys. In Co-Al-W-Ni-Cr alloys, the x(Al)/x(W) ratio has an effect on the distribution coefficient KNi^γ′/γ of Ni between γ and γ′ phases. KNi^γ′/γ has a maximum value of 1.24 when x(Al)/x(W) ratio is 2.60. The results can be used for the developing new-type Co-based superalloy.