This study was conducted to evaluate the characteristics of geosmin production of Anabaena circinalis under different environmental condition. The test cyanobacterium was isolated from Lake Paldang. The growth rate and geosmin production of A. circinalis were examined with different variables including temperature (10, 15, 20, 25℃), light intensity (60, 120, 240 μmol photons m-2 s-1), and phosphorus concentration (0.01, 0.05, 0.25, 0.50, 1.00 mg L-1). The highest growth rate and chlorophyll-a (Chl-a) concentration appeared at 25℃, 60 μmol photons m-2 s-1 and 1.00 mgP L-1 for temperature, light intensity, and P concentration, respectively. Total geosmin production was highest at the optimal growth condition of each variable, while chlorophyll-specific geosmin production (the ratio of geosmin to Chl-a) was higher at the less favorable growth condition, indicating high potential of the off-flavor problem during low temperature period, e.g., late fall and early winter. Our results demonstrated that geosmin production of A. circinalis was directly related to chlorophyll synthesis and varied with cellular growth condition.