A three-dimensional primitive equation model (the Princeton Ocean Model, often called POM) has been implemented for simulating Typhoon Holly generated in the tropical Pacific Ocean. This is the first time that a study of this type, previously used mostly for coastal, regional simulations, has been implemented for the northwestern Pacific Ocean, from 24¿N to 52¿N, including the East China Sea, the Yellow Sea, and the East (Japan) Sea. In the open ocean the model circulation, sea surface elevation, and temperature distribution with the passage of Holly are described; the results are in part compared with observation in the Korea (Tsushima) Strait. The model reproduces well several prominent features obtained in the observation such as a rapid increase of temperature in the Korea Strait during the passage of Typhoon Holly, in August 1984, and reasonably explains how they happened. Around the vicinity of the typhoon center, the model temperature field successfully presents sea surface cooling in the open ocean, having been frequently observed in the past. The model also suggests that a coastal jet around the Korea Strait and a cyclonic eddy field behind Holly in the East China Sea play an important role in the oceanic conditions although they have not yet been identified by observations.