A regional distribution system is studied, which is composed of a distribution center and multiple retailers among
whom each plans its own demand in a fixed replenishment interval as a random variable obeying a graded symmetric
distribution on the finite interval and is able to determine independently its optimal replenish-up-to level. In such a case, the distribution center replenishes the retailer’s inventories circularly and periodically, and its fixed period is the same to the fixed replenishment interval as the retailers planned. The retailer’s customer demand is assumed to take place evenly. The control policies are thus schemed out to both retailer’s optimal replenish-up-to level and distribution center’s order. Finally, a practical example shows the effectiveness of the model.