Abstract: This paper analyzed the correlation between blue-green algae density and water temperature based on the blue-green algae density and water temperature day-to-day data that observed from Gonghu Xidong,Gonghu Shazhu and Meilianghu Xiaowanli in 2007.It was found that: in Xidong,correlation between blue-green algae density and water temperature of 23 to 32,39 preceding days was the best,and cumulative temperature of 13 to 18,24 to 25 was also the best.In Shazhu,correlation between density and water temperature of 1 to 46,100,113,118 preceding days was the best,and cumulative temperature of 2 to 34 was also the best.In Xiaowanli,correlation between density and water temperature of 1 to 42,65 to 67,82 to 84,96 preceding days was the best,and cumulative temperature of 2 to 38 preceding cumulative days was also the best.

Key words: Blue-green algae density, Growth, Water temperature