Abstract: An improved LMS blind space-time multiuser detection method based on the Rosens gradient projection to realize in multipath CDMA channels is presented. Comparison with the original method, the proposed method has advantages in complexity and requirement of the system. However, the results of simulation comparison illustrate that the detection performance of the proposed multiuser space-time processing method do not deteriorate, and prove that this method has advantage over the original method in the competition of market.