This paper presents various blind equalization algorithms called CMA, DM-CMA, SGA-DM-CMA, MCMA, DM-MCMA and SGA-DM-MCMA. This paper discuss some of advantages or disadvantages provided by these algorithms before applied to the practical high-order QAM system. From the results of simulation, we can verify that all of these algorithms discussed in this paper operate very well, Among the various algorithms, SGA-DM-MCMA algorithm shows best performance in terms of ISI characteristics.