Abstract: Subliminal semantic activation（SSA）has been researched for 20 years. With the development of the research, four research patterns have emerged. They are congruent and incongruent pattern, indirect without direct effect pattern, indirect greater than direct effect pattern and regression analysis strategy pattern. The present paper gave a general review of the four patterns and made a brief introduction of the theory models on the subliminal semantic activation research. The mechanism of unconsciousness in SSA was discussed in detail with spreading priming model, response competing model and compound cue model.

Key words: unconscious, priming, subliminal stimuli, subliminal semantic activation