Dongsha Island has Taiwan¡¦s only well developed and integrated coral atoll ecosystem. The numbers of fish species and coral varieties in its waters have topped 679 and 286 respectively, which illustrates its biodiversity and wealth of fishery resources; therefore, it has drawn plenty of Chinese fishing boats to illegally enter into the area for fishing. Over the years, the fishery resources and terrain ecology of the Dongsha Island have been damaged as a result of illegal fishing. On the other hand, even though Taiwan¡¦s Coast Guard Administration in charge of patrolling the waters of the Dongsha Marine National Park, due to the vast sea area and varying depths of the atoll, the effect of the law enforcement on the vessels is limited, and cannot provide effective deterrence. By using existing information technology to gain knowledge on the distribution of the Chinese fishing boats, this study proposes to make the most of the limited law enforcement capacity to enhance the efficiency of law enforcement. With the coastal radar station established by Taiwan¡¦s Coast Guard Administration in 2003, this study scanned the waters around the clock and digitally journalized the data regarding times and locations of the voyages of the fishing boats, to further explore the time and space distribution of the Chinese fishing boats at the Dongsha atoll. Based on the annual, quarterly, monthly, day to night and tidal periods, five periods in total, this study used the Geographic Information System (GIS) to map out the distribution of the Chinese fishing boats, and probed into the distribution patterns in different times and spaces. The results will provide a scientific reference for law enforcement; it is hoped that the law will be effectively enforced and the ecological environment will be well preserved under limited resources. The study results indicate that the Chinese fishing boats operating at the Dongsha atoll are mainly small boats; a large boat can carry 10 to 30 small boats. Furthermore, the fishery catches are mainly live fish, sea cucumbers and conches, and are mostly carried back to the port by transport vessels for sale. The Chinese fishing boats often gather at two hot spots of the south atoll platform and the north atoll platform. In terms of the distribution of seasonal gathering, the study found that most of the Chinese fishing boats return home for the Chinese New Year holiday, the gathering density is higher during full moon periods and the gathering may slightly move towards the north when affected by the southwest monsoon. These results can serve as an important reference for Dongsha Marine National Park¡¦s resource management and Coast Guard Administration¡¦s sea area law enforcement.