This study investigated effects of pH-depended inorganic carbon (IC) species and pH on algal growth in the sewage simulation system, and fruitfully discussed the relationships among IC, pH and algal growth by the Monod kinetics. Results showed HCO3 significantly increased algal growth by 3.17-6.52 times than that of CO32 and/or glucose when the value of pH was in the range of 8.0-9.5, and also the preferentially utilized indicated by the affinity coefficient (K-p) of HCO3, CO32 and glucose (0.17, 15.14 and 31.22, respectively). Meanwhile, the same pH range facilitated HCO3 to become a dominated species (e.g., 48.80-93.19% of total IC). More importantly, good linear correlations pairwise existed among pH, IC species and algae growth. These results suggested pH plays a critical role in regulation of IC species and algae growth, which would be an efficient method to control the IC discharge from sewage effluents and weaken bloom outbreak. (C) 2016 Elsevier Ltd. All rights reserved.