Purpose of Review Drug addiction starts from recreational drug use, gradually becomes habitual or even compulsive. However, after exposure to addictive drugs, only 20% of individuals finally fall into a vicious cycle of addiction. As the number of addicts worldwide increases year by year, the need for understanding the neural basis underlying addiction is in high demand. Recent Findings The intrastriatal functional shifts have been widely recognized to contribute to addiction development, where the nucleus accumbens permits the devolution of its control over behaviour to the dorsal striatum. In addition, compulsive drug seeking and taking have been taken as maladaptive habits, coupling with impaired goal-directed behaviour, thus habitual system dominant behaviour in spite of punishment. However, this hypothesis has not fully been proven at the level of neural mechanisms. Here we elaborated the function of the striatum at the different stages of addiction within the associative learning theory framework to highlight the potentially vulnerable targets of addictive drugs. Furthermore, based on current findings, we proposed new possibilities to explain compulsive drug-seeking behaviour.