中文摘要：

根据1997～2000年在东海海域23°30′～33°N、118°30′～128°E4个季节海洋调查资料，运用定量、定性方法，探讨东海海樽类（Thaliacea）种类组成、物种数平面分布和多样性变化及与环境的关系。结果显示，东海调查水域共发现浮游海樽类20种，夏季16种，春季12种，秋季11种，冬季9种；季节更替率显示，海樽类物种季节更替，从春季到冬季，是温度的季节变化和暖流势力消长共同作用的结果；从冬季到春季，主要受暖流势力增长的影响。春季海樽类物种数与表温和底盐相关，夏季与10m水层温度和盐度相关；秋季相关性不明显，冬季与表温相关。东海海樽种类季节特征和地区特征的形成，主要与暖流势力消长有关。双尾纽鳃樽东方亚种（Thalia　democratica　orientalis）等7个种是东海的常见种，羽环纽鳃樽（Cyclosalpa　pinnata）等6个种是次常见种，其余则是稀有种。东海各分海区海樽类多样性指数大多较低，主要是由于优势种具有很强的聚集性，这种种间和各站位之间分配的不均匀性，是多样性指数较低的最主要的原因。

英文摘要：

On the basis of the data from four marine investigation in the East China Sea （23°30′～33°N,118°30′～128°E） in 1997～2000, this paper discussed the species composition and the diversity of Thaliacea, and the relations between Thaliacea and environment as well. Investigation results showed that altogether 20 species of Thaliacea appeared in the investigation areas, 16 of them in summer, 15 in spring, 11 in autumn and 9 in winter. According to the calculated alternation fraction （R）, the seasonal alternation of the species from spring to winter resulted from the joint action of seasonal change of temperature and the growth and decline of warm current influence. From winter to spring, however, the alternation was mainly affected by the growth of warm current influence. Species numbers in spring was related to both the surface water temperature and bottom salinity, whereas water temperature and salinity at the depth of 10 m had a bearing on species numbers in summer. In autumn, both temperature and salinity had no significant effect on species distribution. In winter, however, the surface water temperature turned into a influence factor. The growth and decline of warm current influence played a very important role in the forming of seasonal and regional characters of species composition. Among the twenty species in the East China Sea, seven are common species, including Creseis acicula , Thalia democratica orientalis , Doliolum denticulatum , Dolioetta gegenbauri , Doliolum sp., D. nationalis, Thalia democratica and Brooksia rostrata , six are subordinate common species, including T. democratica echinata, Weelia cylindrical, Cyclosalpa pinnata, C. pinnata polae, C. floridana and Pyrosorma atlanticum Peron, and the rest are rare species, namely, C. pinnata quadriluminis, C. pinnata sewelli, Cyclosalpa sp., Pyrosoma sp., Ritteriella amboinensis and R. picteti. The dominant species of Thaliacea have strong concentrating nature, resulting in the uneven distribution of the individual numbers of various