Abstract: Inver function transformation has been conducted on the approximation analytical solution describing the quasi-steady radial flow dispersion in this paper.Based on the transformed expression,the liner equations in the case of being of c-t and c-r data have been established.The dependent and independent variables in those equations are the functions of test data,and the linear constants include the parameters to be estimated.So if the test data are conversed suitably,the linear constants may be computed by the means of linear regression method or linear graphical method,and finally the longitudinal disperse coefficient and effect porosity of aquifer may be computed.The practical example shows that the results of the method presented here is of high accuracy.