This work was to investigate the formation potential of trihalomethane(THM) and trichloronitromethane (TCNM) for algae extracellular organic matter (EOM) and intracellular organic matter (IOM) in different algae growth stages and chlorine dosages, and the effects on the production of THMs and TCNM during chlorination were further studied. Results showed that EOM and IOM had high concentrations of TOC and DON, while low organic component of aromatic structure and unsaturated double bonds. The yields of TCNM from chlorinated EOM increased from high biomass logarithmic phase to declinephase.However, TCNM of IOM followed an increasing and then decreasing pattern with the extent of growth days. The pattern of THMsFP was similar to TCNMFP, but the concentrations of THMs were much higher than TCNM. TCNM increased with chlorine dosages during EOM chlorinated, for IOM, however, the concentration of TCNM firstly increased and then decreased. The maximum TCNM yield of IOM appeared on chlorine dosage of 30 mg/L.TCM was the dominant fraction of THMs. In stationary phase, THMs produced from EOM and IOM gradually increased with chlorine dosage from 20 to 30 mg/L, but increased significantly at more than 30 mg/L.