Current research on belief rule base(BRB) focuses on single BRB system, however, the reasoning performance of single BRB system is influenced by the values of parameters. And the uneven distribution or small amount of training data can lead to the incompleteness of training parameters, which makes the locality of information for decision provided by reasoning results. To solve these problems, this paper proposes BRB-ensemble system base in gradient descent algorithm(GDA) via combining the Bagging and Ada Bo...