This paper deals with the estimation of limiting distribution parameters, which have a close relation with product reliability characteristics in reliability test. Among the many kinds of estimation methods, probability paper is commonly used. The limiting probability paper is very convenient, but it has a great disadvantage in estimation accuracy by plotting method. It is very difficult to get the same results even if one use the same data several times. A computer program for the regression method is used for the parameter estimation to reduce these errors. Especially, the computer graphic program was written in GW-BASIC 3.22 language and a couple of running examples for user's reference appears in the appendix part.