Abstract: Multiple-channel cooperative spectrum sensing in cognitive radio networks (CRN) based on cognitive radios with single antenna had been widely researched. However, it should be studied more to get the optimal antenna assignment in multiple-channel coordinated spectrum sensing for multiple antennas based cognitive radio networks when multi-antenna cognitive radios can flexibly select their antennas to apply spatial diversity reception. To solve this problem, we modeled it as an optimization problem with the constraint of the maximum false alarm probability of each channel and goal of minimizing the sum of misdetection probability over all the channels, and proposed two methods, branch and bound based method and greedy based heuristic method. The former can get the optimal strategy with high complexity, while the latter can reduce complexity obviously at the price of little loss of performance of detection and achieve a good trade-off between performance of detection and complexity, and care about the fairness to a certain degree on protecting primary users from interference of cognitive radios on each channel.