In this paper, we investgate variation of phase and magnitude characteristics which become different as the variables of DGS are changed and propose the new method to easily decide the best optimum DGS pattern taking advantage of this trend. Generalized Chebyshev(GC) low pass filter(LPF) is designed by using DGS obtained from this method GC DGS LPF is more available for filter application than Chevyshev DGS LPF because GC LPF have parallel resonators as series circuits, therefore unlikely Chebyshev LPF, transform step of the series elements can be omitted. By using the proposed method, GC DGS LPF(N=5) and as a subject of comparison, conventional Chbyshev LPF(N=7) are designed and implementation. From the comparison of the measured data, we confirmed that the implemented GC DGS 5th order LPF have much better cutoff characteristics and reduce by 0.58 times size, on the other hand the stop bandwidth become widen about 1.57 times or more in comparison with the conventional Chevyshev 7th order LPF.