In the past, expert systems exploited mainly the EMYCIN model andthe PROSPECTOR model to deal with uncertainties. In other words, a lotof stand-alone expert systems which use these two models are available.If we can use the Internet to couple them together, their performancewill be improved through cooperation. This is because theproblem-solving ability of expert systems is greatly improved by the wayof cooperation among different expert systems in a distributed expertsystem. Cooperation between different expert systems with these twoheterogeneous uncertain reasoning models is essentially based on thetransformations of uncertainties of propositions between these twomodels. In this paper, we discovered the exactly isomorphictransformations uncertainties between uncertain reasoning models, asused by EMYCIN and PROSPECTOR.