Abstract: Check gates are important devices for regulating canal operation, a key factor of canal hydraulic response. This study investigates the influence of gate regulation on channel hydraulic response to increasing diversion flux, using a case study of the Xiao Canal operation for the east route of South-to-North Water Diversion project. We adopt hydraulic response indicators of water stage drop rate, water stage peak drop, and transition time at the diversion intake, examine the sensitivity of these response indicators to gate regulation, and develop a system of sensitivity indexes applicable to evaluation of the effects of the gate regulating range and gate distance from the intake on all the response indicators. The results show that the hydraulic response is more sensitive to the regulating range than gate distance.