To explore variation of dissolved inorganic carbon content (DIC) caused by cyanobacterial blooms and provide a basis for formulating effective preventive and control measures of cyanobacterial blooms, the concentration of inorganic carbon and the concentration of planktonic algae were studied by sampling method, and the distribution and variation of the DIC and physicochemical factors in the ecological restoration area of Fubao Bay of Dianchi Lake were analyzed. Results indicated that the distribution of chlorophyll-a was significantly positive correlated with CO32- (P < 0.01) and pH values (P < 0.05); and the distribution of chlorophyll-a was significantly negative correlated with CO2 (P < 0.01), DIC and HCO3- (P < 0.05). In conclusion, the outbreak and extinction of cyanobacterial blooms is one of the important reasons for the variation of inorganic carbon form and concentration.