A landing position/orientation of a foot (22) to be landed in a landing action of a robot (1) such as a biped mobile robot or the like is estimated, and a desired footstep path for the robot (1) is set up. Based on the estimated landing position/orientation and the desired footstep path, a future desired landing position/orientation is determined in order to cause actual footsteps of the robot (1) (a sequence of landing positions/orientations of the foot (22)) to approach desired footsteps. Using at least the determined desired landing position/orientation, a desired gait for the robot (1) is determined, and the robot (1) is controlled in operation depending on the desired gait. For determining the desired landing position/orientation, mechanism-dependent limitations of the robot (1) such as an interference between the legs thereof, etc., and limiting conditions of an allowable range in which a desired ZMP can exist are taken into consideration.