The synoptic feature of the surface fronts in the East China Sea has been studied mostly by using satellite imageries, e.g., AVHRR-derived infrared images (He et al., 1995; Ning et al., 1998; Hickox et al., 2000). Though the details are not the same, the previous studies generally show that three kinds of regional (thermal) fronts exist in the area: the Kuroshio front in the region of shelf break, fronts associated with the Taiwan Warm Current, Tsushima Warm Current in the mid-shelf, and Cheju Warm Current Water (Lie et al., 2000) front and China Coastal Water (including the Yangtze River Diluted Water) front near the coasts. However, because the satellite infrared imageries cannot describe the surface salinity fronts during the warm season, the seasonality of the fronts is not fully understood, especially in the shelf area. As a continuation of the presentation by Lee et al. (1997), this study describes seasonal characteristics of the frontal patterns and the vertical fine structure in the fronts based on the temperature and salinity data collected by Korea Ocean Research and Development Institute during the period of 1993-1999.