Where hydraulic characteristics of ship-lock filling and emptying system are conced, there are much bigger differences between prototype and model experiments.Based on the results of the prototype experiments for the Three Gorges Project (TGP), experiments on the feedback model were conducted of the ship-lock filling and emptying system, by means of technologies of drag reduction, under similar conditions as the operation of the prototype project.The experimental results show that the difference of drag coefficient reached -44% between the prototype and the model for the filling and emptying system of the ship-lock No.3 for TGP and the difference of discharge coefficient was about 33% between them.The technologies of drag reduction are more efficient in the simulation of a ship-lock filling and emptying system in order to be consistent for discharge, water level, time average pressure and pulsating pressure between prototypes and models.