Most studies concerning OPEC’s behavior were based on traditional market microstructure. However, the assumptions about oil market structure are either very rigorous or rather fuzzy. This paper demonstrates the rationality and necessity of OPEC’s price band policy by using the game theory. We conclude that OPEC has the incentive to limit its price within a specific range if the game period is sufficiently long. This incentive comes either from preference for long-term interest or from future expectations. In such a way, OPEC tries its best to maximize its profit with the quota-price dual policy and plays a price stabilizing role in the future world oil market. Most studies concerning OPEC’s behavior were based on traditional market microstructure. However, the assumptions about oil market structure are either very very rigorous or rather fuzzy. This paper demonstrates the rationality and necessity of OPEC’s price band policy by using the game theory. We conclude that OPEC has the incentive to limit its price within a specific range if the game period is substantially long. This way comes either from preference for long-term interest or from future expectations. quota-price dual policy and plays a price stabilizing role in the future world oil market.