A gait state recognizing apparatus may include an inertial measurement unit (IMU) sensor configured to measure a movement of at least one leg of a user and a processor configured to calculate a rotation angle and an angular velocity of the at least one leg based on the measured movement of the at least one leg, and the processor may be configured to calculate the rotation angle of the at least one leg relative to a direction of gravity from the movement of the at least one leg and the angular velocity of the at least one leg relative to the direction of gravity based on a trend of the rotation angle.