Abstract: A least mean squares (LMS)-least squares (LS) smart antenna adaptive interference suppression algorithm is proposed for the smart antenna adaptive interference suppression system based on the training sequence. The new method firstly uses small snapshot number LS method to provide initial weight vector for LMS method, then the weight vector is updated by the LMS algorithm. Through complexity analysis for the three kinds of algorithm LS, LMS and LS-LMS, the conclusion can be drawn that the computational burden of the new algorithm is smaller than the other two algorithms. When the snapshot number is large or array element and snapshot number both are large, new method can effectively improve the computational efficiency. Simulation results show that the new method outperforms LMS algorithm when the number of snapshots is few. Regardless of the interference environments, with the increasing of the number of snapshots, the new method converges to the optimal value with a faster convergence speed.