Bench-scale kinetics tests were conducted to evaluate the formation of disinfection by-products (DBPs), as well as the odorant degradation, during chlorination of representative algal odorants. beta-Cyclocitral degradation better followed a pseudo first order kinetics pattern, while the decomposition behaviors of beta-ionone and heptanal were better described by the pseudo second order kinetics. Trihalomethanes (THMs) were commonly found during chlorination of beta-cyclocitral, beta-ionone and heptanal, but dimethylsulfide and dimethyl trisulfide did not contribute to the THM formation. In contrast, haloacetic acids (HAAs) were undetectable in all the samples. During chlorination of beta-cyclocitral, beta-ionone and heptanal, primary intermediate oxidation products were identified. Particularly, beta-ionone was a significant THM precursor. Typically, the formation of chloroform was favored with the increasing pH from 2 to 12. In the tests to chlorinate raw water collected from the Taihu Lake, China, odorants in Micro cystis aeruginosa could contribute to the chloroform formation. beta-Cyclocitral and beta-ionone, accounting for 0.021% mu g/mu g DOC and 0.0027% mu g/mu g DOC of intracellular organic matter (IOM), produced 0.98% and 0.78% chloroform of IOM formed, respectively. This study demonstrated that algal odorants played a critical role in the DBP formation during chlorination in water treatment. (C) 2011 Elsevier B.V. All rights reserved.