Abstract: In this paper, amathematicalmodelof flood routing for Three-Gorge-Reservoir-centered flood control system is developed.The system is decoupled into two subsystems, namely the upper-dam-site subsystem and the dam-site-Hukou sub system，according to its nature.The flood routing is carried outw ith hydrology methods. Testedw ith observed data of 1981 and 1983 flood events, it appears that the model holds satisfactory accuracy.The model also has advantages over past modelswith the introduction of computer-aided techniques.