Abstract: Fuzzy cognitive map （FCM） fails to represent the measures of uncertain causal relationships, spatial and temporal characteristic in causal relationships, and the uncertainty of expert’s knowledge Conditional probability and belief knowledge database are introduced to solve those problems, and belief knowledge database based probabilistic fuzzy cognitive map （BKPFCM） is presented In BKPFCM, the conditional probability and belief knowledge database express the measures of uncertain causal relationships and expert’s knowledge with uncertainty, so, the simulating capability of FCM is extended naturally Finally, experiments show that BKPFCM is more flexible and robust than FCM