A method to determine the mass transfer coefficient from adsorption curves and desorption depletion curves has been proposed by one of authors. The method used time difference at the points of c/c(0)=0.1 and 0.9 in elution curves. By using second central moments of step response in place of Lit better results are expected. In this work, nondimensional moments were numerically calculated and charts were given to determine mass transfer rate. This method was applied to some experimental adsorption and desorption curves, and K(F)a(v) values were obtained with high reliability.