Abstract: Owing to the coupling among the vectors to be optimized, the problem becomes non-convex and non-linear. Accordingly, a centralized coordinated beamforming design method was proposed by constraining the leakage interference and using the semi-definite relaxation, and on the base of it, a decentralized algorithm was also proposed by decomposing the centralized design problem into a group of sub-problems on each cell’s base by using dual decomposition. Simulation results show that the proposed schemes make effective reduction in power consumption while guarantee the legal users’ secrecy rate requirement and the cognitive interference constraint. Moreover, the proposed decentralized method not only reduces the computational complexity, but also has the same performance as the centralized algorithm.