Abstract: Based on the two-dimensional non-gradient system, the adaptive landscape is constructed. The qualitative analysis of the system is gotten in the action of selection, recombination and the linkage disequilibrium. And for the first time, through the method of constructing the generalized Lyapunov function, the adaptive landscape is given quantitatively. It is clarified that the detailed balance and zero curl is not the criterion for the existence of the adaptive landscape.