Abstract: In order to solve the problem of high sidelobe level and anti-jammering performance degradation in larger sparse MIMO radar, a modified LCMV algorithm based on designing constraints is proposed. In this proposed method, the low sidelobe weights are calculated by inserting virtual dense interference;and the nulls are formed by modified constraints in LCMV algorithm. Thus the pattern can maintain low side-lobe level while forming nulls in specified region. The proposed method can achieve desirable interference suppression and low side-lobe level simultaneously, especially under the condition of low free degree of system. Simulation results prove the efficiency of this modified LCMV algorithm.