This study was performed to develop the method which could collect completely the cancer cases in Pusan Cancer Registry(PCR). The definite goals were ¨c to see the feasibility and completeness of PCR connected with Central Cancer Registry Program(CCRP), by calculating omitting rates based on utilization rate of hospitals in Pusan and registered hospitals ¨e to evaluate the possibility of generalization to other cities-Taegu, Incheun, Kwangju, Taejeon. Data sources were CCRP and claims from the Korea Medical Insurance Corporation (KMIC). l) In case of using data of the registered and unregistered hospitals in each city, the expected omitting rates were 6.2%(CCRP)-8.5%(KMIC) in Pusan, 4.7% in Taegu, 42.7% in Incheun, 26.3% in Kwangju and 13.5% in Taejeon, respectively. They was suggested to be transferred to the hospitals in other areas from doctor's offices directly. 2) In case of using data of CCR, the expected omitting rates were 9.3% in Pusan, 3.1% in Taegu, 4.2% in Incheun, 5.4% in Kwangju and 0.9% in Taejeon, respectively. 3) In case of using both two data resources -CCR and the unregistered hospitals in each city- the expected omitting rates were 1.2% in Pusan, 1.5% in Taegu, 0.0% in Incheun, 1.2% in Kwangju and 0.0% in Taejeon, respectively. Almost all patients using only the hospital in other areas visited registered hospital which have attended CCR. We could ensure about 100% completeness, combining the CCR and an active surveillance at unregistered hospitals. This model could be one of the most efficient population-based cancer registry in Korea.