Abstract: Multi-year variations of temperature and salinity at the 137°E section are analysed systematically. Main results are as follows:(1)In the 100 m layer, an anomalous low temperature occurred in certain areas of the low latitude in certain years, which is relative to the El Niño event. Analyses also show that the existence of the Mindanao eddy is main reason causing the low tempera-ture occurring near area of 6°～8°N at the 137°E section. (2)During El Niño, the range surrounded by 28℃ isotherm in winter is less than its multi-year averaged value. (3)The subsurface high-salinity water in winter can be classified into four types:strong, substroug, middle and weak.