The neural network of our brain processes all kinds of information through excitatory and inhibitory synapses. Although there are less inhibitory neurons in the brain, they are extremely important in regulating information processing and neuronal plasticity. Further more, various of brain dysfunctions are related to the disfunction of inhibitory system. Inter-cortical inhibition, which includes feedforward and feedback projections, mediates the inhibitory effects between different brain areas. Intra-cortical inhibition, or mutual inhibition, mediates inhibitory interactions between neurons nearby but with different preferences. In this review, we introduced the behavioral performance of two kinds of inbitiory mechanisms, using center-surround suppression and motion repulsion paradigm as examples. Then we related the changes of cortical inhibition to aging and two typical mental disorders.