关键词: Bayesian网络, 结构学习, 条件独立性, 条件互信息, 条件依赖度

Abstract: Bayesian network is a forceful tool to practise inference of uncertainty. It combines graphic theories and probability ones, which can conveniently express and calculate the probability of interesting events and at the same time provide a compact, visual and effective graphic expression for the dependant relationship among the entities. On the basis of testing information independence theory, the test of CI（conditional independence） was carried out on all the joints in the Bayesian network to find out the conditionally dependant relations among them. Then an effective algorithm of Bayesian network structural learning was worked out, which only needed CI testing of O（N²） times.

Key words: Bayesian network, structural learning, Conditional Independence(CI), conditionally mutual, information, degree of conditional independence