The purpose of this article is to introduce the concept ofO-Kiloss to the inference of genetic linkage. The prior information proposed by Elston and Lange (1975) was used. To help geneticists to understand the implications of the loss function and the Bayes decision rule, the Bayes decision procedure proposed in this article was suggested to be treated as a conventional test statistic. Then it seems almost natural to compare the performance of power of the statistic proposed here with that of the lod score. The simulation result shows that the Bayes decision procedure proposed here and the lod score are of almost equivalent power. This may show that the prior distribution for linkage, derived by Elston and Lange (1975), truly reflects the information about the human gene map and the size of chromosomes.