A gait state determination apparatus includes a foot attachment part disposed in the walking assistance apparatus, the foot attachment part being configured to be attached to a user's foot, pressure detection means disposed in the foot attachment part, the pressure detection means being configured to detect a pressure exerted on a user's sole, pressure center calculation means for successively calculating a center position of a pressure exerted on the sole during a user's gait motion based on the pressure on the sole detected by the pressure detection means, and motion determination mean 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.
