Abstract: The paper reviews recent research about decision making and its underlying brain mechanism based on rodent models. First, the definition of decision making and animal models are introduced. Second, on the basis of these models three common psychological processes and their brain mechanism are summarized: calculating, motivation and memory. Finally, the relationship between decision making and drug addiction is discussed for further thought, which includes the impact of drugs on decision making and the relationship between individual difference on decision making and susceptibility to addiction

Key words: decision making, brain mechanism, drug addiction, rodent model