中文摘要：

2006年8-10月对西藏阿里地区21个湖泊的浮游生物作了初步调查,采得44个浮游生物样品和22个水化学样品。经鉴定分析得浮游植物105种（变种）,分属5门49属,其中硅藻门19属63种（变种）,占总种数的60%;浮游动物14种,分属3门11属,其中亚洲后镖水蚤（Metadiaptomus asiaticus Uljanirs）为西藏首次记录。有螺旋藻、盐藻、西藏拟溞、卤虫等经济种分布的湖泊数分别为8、3、5、12个。浮游生物物种多度随盐度升高而降低,统计分析表明,在0.31-300.71g/L盐度范围内,浮游生物物种多度与盐度存在不显著负相关关系（r2=-0.05,p〉0.05）。文章讨论了西藏拟溞与桡足类之间存在的季节性种群更替现象,以及硅藻在这一现象中可能存在的重要作用。最后对盐湖生物资源特别是西藏拟溞的开发利用提出了设想。

英文摘要：

The study was undertaken from August to December in 2006. 18 saline lakes and 3 subsaline lakes in Ali region, Tibet , had been investigated. The salinity ranged from 0.31 g/L to 300.71 g/L. 44 biological samples and 22 hydrochemical samples were collected. One hundred and five species of phytoplankton and fourteen species of zooplankton, belonged to forty nine and eleven genera respectively, were identified. Diatoms were dominant in species richness by 60 percentage. Metadiaptomus asiaticus Uljanirs was reported firstly in Tibet. Spirulina spp. , Dunaliella salina, Daphniopsis tibetana Sars, Artemia spp. distributed in 8, 3, 5 and 12 lakes, respectively. No plankton was identified in Cabu Co and Jeze Chaka because of high salinity and（or） some unknown factors else. Plankton species richness decreased as salinity increasing. The correlationship between plankton species richness and salinity was not significant （r^2= -0.05 ,p〉0.05） with salinity ranged from 0.31 g/L to 300.71 g/L, according to statistics. This paper showed a view to explain the seasonal population change between Daphniopsis tibetana Sars and Copepoda. The result suggested that diatoms, such as cyclotella spp. , played an important role to this phenomenon. Some advices on the exploitation of saline lake bioresources, especially Daphniopsis tibetana Sars, were given at the end.