Multiagent technologies enable us to explore their sociological and psychological foundations. A medical diagnostic support system is built using this. Moreover, We think that the data inputted can acquire higher diagnostic accuracy by sorting out using a determination table. In this paper, the recurrence diagnostic system of cancer is built and the output error of Mul-tiagents learning method into the usual Neural Network and a Rough Neural Network and Genetic Programming be compared. The data of the prostatic cancer offered by the medical institution and a renal cancer was used for verification of a system.