It is necessary to solve the characteristic of an atmospheric boundary layer or a strong wind in the case of construction of a large-sized structure. A wind tunnel experiment as the analysis for a natural wind is popular method. It is important to produce the flow which has the same turbulent characteristic as the natural wind in a tunnel. This research aims at reproducing the turbulent flow of the natural wind in a wind tunnel. As an active method, time changing the number of rotations of the fan in a wind tunnel equipment is carried out. Furthermore, the method of arranging a fan one by one to turn reverse rotation, which called Quasi-Grid method was used. As the current research, in addition to the conventional active control, the quasi-grid method was introduced. The result was obtained from the combination of quasi-grid method will be effective as a preset value at the time of reproducing arbitrary wind velocity in a wind tunnel. It turned out that the frequency region of the inertia sub range to be generated turbulent flow by spectral analysis.