A variable nonlinear feedback (VNF) method was proposed to control chaotic systems.Control principles and the technique to select the feedback coefficients were introduced. This control method was theoretically studied with a single-mode laser Haken-Lorenz system. The numerical simulation results showed that the maximum Lyapunov exponent of the system can be changed from positive values into negative ones by appropriately selecting feedback coefficients,and the orbits of the system can be changed from the chaotic attractor into the periodic orbits in phase space,the numbers of periodic orbits are 2ⁿ×3^mp(n,m are integers). Comparison between the VNF method and the linear feedback method has been made which shows that the former is speeder,simpler and more efficient.