Front detection and declouding algorithms developed at the URI have been applied to the 12-year (1985--1996) Pathfinder SST data set to produce the first comprehensive, objectively derived, year-round climatology of ocean thermal fronts in the eastern China Seas, from 24 ¿N to 41 ¿N. Ten fronts have been distinguished, namely Kuroshio, Zhejiang-Fujian, Jiangsu, Shandong Peninsula, Bohai Sea, Seohan Bay, Kyunggi Bay, Western and Eastern Chejudo (South Korean Coastal Front), and Yangtze Bank Ring Front. The fronts are seasonally persistent: they emerge and disappear in the same seasons of different years. The frontal pattern remains fairly stable from one year to another, whereas individual fronts display different modes of seasonal variability. ¿ 2000 American Geophysical Union