This poper describes the study on 3 dB wide hand coupler in two-type waveguide model. Two fibers of stepping refraction index were used. ho coupling zone of one fiber become thin by etch method, to make a combination waveguide of two quasi cone shaped. The variational and coupled wave theory, are adoped to analyse the waistzone and trapezvidal zone. Toeal POwer was equal to the sum of two pet coupled power at any POint of the coupler. Using parameter of fiber and she of combination waveguide transverse sect