Abstract:The bacterial abundance and active bacterial abundance of water and algae attached, as well as the Chl.a and nutrient concentrations, were investigated, and the metabolism coupling between algae and bacteria were also discussed. The results showed: 1) The bacterial abundances of water increased with the Chl.a concentrations increasing(r2=0.466, P<0.05), although the peak value was delayed with the Chl.a concentration. Variation of the algae attached bacterial abundances were the similar patterns. 2) There was a significantly positive relationship between the active bacterial abundances and total bacterial abundance(r2=0.678,P<0.05). Although the algae attached active bacterial abundance was less than the active bacterial abundance of water, the significantly increased patterns were also founded with the active bacterial abundance of water increasing (r2=0.836, P<0.05). 3)The algae attached bacteria abundances and activities were determined by the algae growth status. The ratio of active algae attached bacteria/total algae attached bacteria was higher than that of total bacteria, and this ratio was increased in the period of May to September during the algal blooms.