A total of 48 algae samples were collected from southern bays of the Donghu  Lake from September in 1963 to December in 1964．The desmids were very plentiful，164 species，75 varieties and 13 forms belonging to 20 genera were identified．Among these，two species，seven varieties and two forms are new to science**，and 12 species，25 varieties and five forms are recorded for the first time in China．The dominant species with frequent occurrence were 11 species and one variety in four seasons．

The result of counting and analysing the samples collected in different seasons  (six  times  for  each)  shows  that  the  number  of  the  taxa  of  Desmids  in  summer  (June  and  August)was the highest，that in autumn and winter (September，October and December)  the next，and that in spring (April) is the lowest．