A control system for a walking assist device includes a ground detecting means having a plurality of force sensors equipped to each foot attachment portion. Each ground sensor selectively outputs a ground state output and non-ground state output in accordance with whether the foot attachment portion is grounded at a position immediately below the ground sensor. The control system is equipped with means that continuously generate reference data for each of the ground detecting means, where the reference data increases and decreases in value in accordance with the change of a total number of the ground sensors generating ground state output in the ground detecting means. Also, a means that determines a mutual desired proportion of the supporting force to be applied to the both leg links from the floor side is provided.
