Abstract: Blind equalization is an adaptive equalization technique without the aid of training sequences. This paper examines several forms of blind equalizers,including Bassgand, High order Cumulant based, Signal detection based and Nonlinear transformation types, it analyzes both the advantages and disadvantages of these equalizers and their relevant algorithms in sequence. Based on results of the examination and analysis, the developing orientations of the research on blind equalizers is clarified.