A gait state determination apparatus includes a foot attachment structure disposed in the walking assistance apparatus, the foot attachment structure to be attached to a foot of a user, pressure detection means, disposed in the foot attachment structure, for detecting a pressure exerted on a sole of the user, pressure center calculation means for successively calculating a center position of a pressure exerted on the sole during a gait motion of the user based on the pressure exerted on the sole detected by the pressure detection means, and motion determination means for determining that it is a timing of a start of forward swinging of the leg to which the walking assistance apparatus is attached when the center position of the pressure calculated by the pressure center calculation means is shifted from a position in a heel region of the sole to a toe region thereof.
