Patterns of recent sea level rise in the East/Japan Sea (EJS) are investigated through the analyses of TOPEX/Poseidon (T/P) sea level anomalies, thermosteric sea level (TSL), and long-term tide gauge data. The 9-year-long T/P analyses reveal average trends of 5.4 ¿ 0.3 mm yr-1 for all of EJS and 6.6 ¿ 0.4 mm yr-1 for the southern EJS. These are much larger than the global rates of 3.1 ¿ 0.4 mm yr-1 reported by Cabanes et al. (2001) and 2.8 ¿ 0.4 mm yr-1 by Cazenave and Nerem (2004). This T/P rate compares relatively well with those from TSL data and tidal sea level gauges, indicating that sea level rise in the EJS is mainly due to thermal expansion. The southern EJS shows a nonuniform sea level trend pattern, with the western part of the Ulleung and Yamato Basins having values of 10 mm yr-1 and larger. This nonuniform pattern is discussed in terms of variable thermal expansions arising from a recent decadal trend in the temperature anomaly in the upper layer of the two basins. The 40-year-long TSL time series also reveals a decadal oscillation in the Ulleung and Yamato Basins that can be explained by interannual to decadal variations in temperature in the upper ocean layers, with weaker anomalies at most of the other EJS locations. It is hypothesized that the long-term oscillation in the southern EJS may be related to the decadal variability of heat content anomaly in the upper 300 m of the Pacific Ocean, as reported by Levitus et al. (2000), and to the north-south migration of the Warm Tsushima Current and eddies in the southern EJS.