Reuse partitioning is an effective concept to get high spectrum efficiency in cellular systems. This paper proposed a dynamic channel assignment(DCA) method named SORP, where the reuse partitioning is self-organized. In this method, each base station has a table, where average power for each channel used so far in its cell and surrounding cells are stored. When a call arrives , the base station measures the output power of the calling mobile station, and selects a channel, which shows the average power closest to the measured power. The channel is used if available , otherwise the second closest candidate is tried. The content of the table for the chosen channel is updated with the average value of the measured power and the power of other mobile stations using the same channel. The power of other mobile stations is broadcasted by their base station. As a consequence of this procedure in each base station, channels that correspond to the same power are grouped autonomously for self-organized reuse partitioning. Performance is compared between the proposed method SORP, the conventional Autonomous Reuse Partitioning (ARP) and random DCA. For traffic capacity, SORP and ARP shows almost the same performance, which is much superior to that of random DCA. For both the number of trails for a channel assignment and the interference time rate, SORP is much better than ARP. Hence, SORP can reduce the occurrence of intracell hand-off and can reach a desired channel quickly, while achieving high traffic capacity.