Abstract: In this paper, an improved staircase approximation method for analysing radially inhomogeneous fibers is advanced. This method combines the concept of the transmission line network with the rigorous mode matching procedure, and a new solving formula is obtained. Thus the procedure of the classical staircase approxi-mation is tremendously simplified. The analyses and computations of the dispersion, the Poynting flux distribution, the group velocity and the differential group delay for several representative radially inhomogeneous fibers of practical interest show that the present method is more succinct, more accurate and more rapidly convergent than the previous staircase approximation method.