At present, test interpretation technology is still based on the rule and theory during 1960s-1980s, which wasn’t be developed and improved further in view of the new problems in field. The field practice and theory comparison have shown that these basic theory and interpretation model diverges obviously appropriate category, and have the singlet, unilateral problem of considered element, which can’t adapt to the quantification description of complex filtrate in porous medium. The basic theory and mathematic model of tracer test interpretation need to develop further, and interpretation means needs to improve corroboratively. From the point of numerical mathematics, the independent variables in reservoirs were found out and the objective function was constructed. Making use of improved real-number-style inheritance-arithmetic, the unitary parameters inversion and interpretation were accomplished in inter well tracer test.