To provide a ground water flow analysis method and its program capable of efficiently performing analysis, by simplifying the operation of making analysis data, when performing the ground water flow analysis which takes into consideration the distribution of inhomogeneous coefficients of permeability.

In a method for acquiring all water heads of the ground water in an analysis region, by giving the coefficients of permeability in the analysis region, to solve the boundary integral equation by using a double-reciprocal boundary element method, the coefficient of permeability K(xm) is given to the points xm(m=1 to M) in the analysis region, and the distribution of the coefficients of permeability K(x) at an arbitrary point x is given as a formula, by using an approximate function f(x, xm) where RBF or CS-RBFs is used. This K(x) expressing the distribution of the coefficients of permeability and its differential form of K(x)/x (here, represents a round d for partial differentiation symbol) are given to the boundary integral equation.