Abstract
There are problems in the field Agent-based social simulation, like construction of internal model of agent and parameter settings. The purpose of this study was solving these problems, using Bayesian Network. The medical insurance market was set as a case study. Bayesian network is constructed by designing a questionnaire about medical insurance. And this produced both parameter setting and construction of internal model. And the goal is to simulate the proposed model in order to provide insight useful for the medical insurance market.