A novel incremental nonlinear detection algorithm is presented for Multiple-Input Multiple-Output (MIMO) system. In this algorithm, the received data at multiple receiver antennas are nonlinearly mapped and then summed with weights. The weight coefficients are incrementally computed to avoid direct computation of the inverse of a matrix, which greatly reduce the computational complexity. Simulation and comparison show that the proposed algorithm can obtain better performance of Bit Error Rate (BER) than linear Minimum Mean Square Error (MMSE).