Abstract: At the most general level, visual masking refers to a reduction in the visibility of an object caused by the appearance of a second object near in space or time. Most of recent studies have focused on the subjects such as features, objects and scene appearances, attentional control mechanisms, and phenomenal awareness. In this paper, we review the classic concepts and methods, and phenomenology of visual masking. Also, recent relevant findings in psychophysics and electrophysiology are reviewed. And then, we outline and evaluate four kinds of important: the perceptual retouch, the dual-channel, the boundary contour system, and the object-substitution. In the end, some difficulties are involved for discussion: the researches in the influence of different stimuli and tasks, the limitation of neuroscience methods, and difficulties of complexity of simulation models. In addition, three hopeful subjects of future development are outlined：neural correlates of conscious and unconscious vision, functional perspective and the model’s evolution.

Key words: visual masking, metacontrast, prime, functional perspective