A control device and a control program of a walking assisting device, wherein a desired assist ratio, which is a desired value of the ratio of a force to be supplied by a walking assisting device in a total tread force of a user relative to the total tread forces is set, the shares of a lifting force to be applied to the user from a seating part which are to be borne by the leg links are determined from the desire assist ratio and the tread forces of the legs of the user measured on the basis of outputs of force sensors, and actuators of the leg links are controlled such that the determined shares of the lifting force are generated from the leg links. Thus, a force required for the user to support himself/herself by his/her legs on a floor can be reduced while reducing the number of parts to be attached to each leg of the user, and an assisting force for achieving such reductions can be properly shared between the leg links corresponding to the legs of the user.