根据东海30°N断面1976—2013年历年2月份表、底层温度、盐度资料,采用经验正交函数(EOF)、谱分析等方法分析了断面温盐的空间分布特征和时间变化特征。结果表明:断面温度空间变化趋势可分为西段和东段,盐度变化可分为西段、中段和东段;表层温度第一模态呈现准平衡趋势且近海比外海温度变化幅度大,底层温度第一模态呈现下降趋势;表层盐度有降低趋势且近海比外海降低趋势大,底层盐度在近年来表现出降低趋势。该断面水温年际变化和El Nio关系密切;盐度短期震荡和El Nio有关系,而长期变化与PDO有关。 Based on the table, bottom temperature and salinity data of the 30 ° N section from 1976 to 2013 in the East China Sea from February 1976 to February 2013, the spatial and temporal distributions of temperature and salinity in the section were analyzed by empirical orthogonal function (EOF) and spectral analysis. The results show that the trend of the spatial variation of the section temperature can be divided into the western section and the eastern section. The salinity changes can be divided into the western section, the middle section and the eastern section. The first mode of the surface temperature shows a quasi-equilibrium trend, The first mode of bottom temperature shows a downward trend; the salinity of surface layer decreases and the offshore tends to decrease more than the open sea, and the salinity of bottom layer shows a decreasing trend in recent years. The interannual variation of water temperature in this section is closely related to El Nio; the salinity short-term concussion is related to El Nio, while the long-term changes are related to PDO.