In recent years, awareness has become one of the most challenging research fields in the life sciences. Accordingly, subliminal perception is an important psychological issue recently. Subliminal perception is a kind of unconscious mental process which can achieve a low level of cognitive processing. The focus of the debate is whether there is a higher level of unconscious processing? In western countries, subliminal information is used to change the audience attitude and behavior. This paper will explore the affection of subliminal perception on decision making. The main conclusions are presented below. (1) The unseen visual cues are processed, and the cognitive mechanisms are different from those of suprarliminal cues. The ERP experimental results show that subjects accepting cues of threshold level (35ms) have highest cognition load and such cues can improve human’s accuracy of visual search. So, subliminal perception is processed at a high cognition level. (2) Unheard music (both happy music and sad music) can cause significant change to human’s skin resistance, but people themselves can’t consciously feel their change of mood. (3) Subliminal perception (both emotional faces and semantic information) can affect human’s decision making. The affection is based on stimuli channel, present way , decision task types and task difficulty. This research enriches the theoretical achievements on decision making and provides enough experimental support for the further study of the mechanism of decision making. In addition, it is very helpful to develop new behavior intervention technology which is more safety and more hidden.