There is no doubt that the Taiwan Warm Current (TWC) flows through the Taiwan Strait in summer and it reaches the East China Sea (ECS) proper, bringing with it a great deal of nutrients. Here satellite temperature, as well as hydrological, satellite-tracked drifter, and 18O data, are used to show that in winter, warm waters from the South China Sea and a branch of the Kuroshio south of Taiwan reach only the southern part of the Taiwan Strait and that in no way do they flow up freely through the northern part of the Taiwan Strait. This is a clear sign that in winter most of the TWC must originate in the Kuroshio, which moves onto the ECS shelf northeast of Taiwan.