中文摘要：

2005—2006年5—9月、12月的两年间，在松花江哈尔滨段水域进行了硅藻植物的调查采集，经观察鉴定，共发现硅藻植物72种43变种3变型，分别隶属于2纲6目9科23属，共计118个分类单位．本文对松花江哈尔滨段水域的环境特征，硅藻植物群落组成、种类丰度的季节性变化进行了研究，利用硅藻植物与环境相关性特点对水质进行了初步评价．研究结果表明松花江段哈尔滨水域的硅藻植物群落，总体来说以普生种类（共计86个分类单位）为每年的常见种类，还有一些嗜碱种类和冷水种类出现；硅藻种类的丰度随季节变化明显，从夏季到秋季逐渐增多．硅藻的群落结构变化主要受pH，温度，TN，BOD5，氨氮的影响，从优势种的组成来看，β-中污以上的污水指示种类数量最多，一些富营养化种类和耐污种类也有出现，说明2005—2006年松花江流域水质污染呈中度至重度污染．

英文摘要：

During May to September and December in 2005 -2006, the diatom communities were investigated in four sampling stations from Songhua River, Harbin. A total of 118 laxa were identified, belonging to 2 classes, 6 orders, 9 families, 23 genera, 72 species, 43 varieties and 3 forms. The environmental characteristics of Songhua River, diatom communities, taxon richness and seasonal variables were examined. Water-quality parameters of Sanghua River in Harbin during 2005 - 2006 were followed as ： waterpH6.8-7.6, TN 0. 68 - 2. 54mg/L, TP0.05-0. 18mg/L, DO 6.45-6.8 mg/L, BOD5 0.68-3. 12mg/L, COD 13.60 - 18.30 mg/L, NH3 -N 0.11 - 1.52mg/L. The dominant species were Gomphonema angustatum, Cyclotella meneghiniana, Cymbella minuta var. pseudogracilis, Melosira granulate etc. Most of taxa （86 taxa） was cosmopolitan, and alkaleseent taxa （Gyrosigma acuminatum, Pinnularia gibba etc. ） and cold water taxa （ Gomphonema olivaceum, Eunotia valida etc. ） were also found. The diatom richness changed with seasons obviously, diatom species were higher in autumn than that in summer. Temperature, pH, TN, BODs and NH3 -N were the main factors affecting the diatom assemblages. The abundance of β-mesosaprobic taxa were most in dominant diatom, which indicated that water quality of Songhua River in Harbin were mesosaprobie to ponutional water seriously.