This paper studied the effects of the number of chlorines in disinfection by-products (DBPs)on their molecular descriptors including LogP, lowest molecular orbital energy(LUMO).highest molecular orbital energy(HOMO), HOMO-LUMO(δE)and dipole moment. The results showed that different classification of organic compounds had different effects on different molecular descriptors. The orders of correlation between number of chlorines and molecular descriptors are as follows: LogP>LUMO>HOMO>4>dipole moment.
