A walking training system comprising: a treadmill including a belt on which a walking trainee is able to perform walking training, the belt being movable in a rotational manner; a walking assistance apparatus that is mountable on a leg portion of the walking trainee and is adapted to assist the walking operation of the walking trainee; and a controller that is adapted to control the rotational operation of the belt and to control the walking assistance apparatus; wherein: the walking training system further comprises a detection unit that is adapted to detect whether the leg portion of the walking trainee on which the walking assistance apparatus has been mounted has performed a walking operation or a stepping operation on the belt, when a start indication signal indicating a start of assistance by the walking assistance apparatus is input to the controller according to an operation by an operator, the controller controls a motor of the walking assistance apparatus to make the walking trainee perform the walking operation or stepping operation, and the controller is adapted to maintain, after the start indication signal is input, an operation prohibition state in which the rotational operation of the belt is not started until the time that the detection unit detects the walking operation or the stepping operation a predetermined number of times and is adapted to cancel the operation prohibition state after the detection unit detects the walking operation or the stepping operation the predetermined number of times. a treadmill including a belt on which a walking trainee is able to perform walking training, the belt being movable in a rotational manner; a walking assistance apparatus that is mountable on a leg portion of the walking trainee and is adapted to assist the walking operation of the walking trainee; and a controller that is adapted to control the rotational operation of the belt and to control the walking assistance apparatus; wherein: the walking training system further comprises a detection unit that is adapted to detect whether the leg portion of the walking trainee on which the walking assistance apparatus has been mounted has performed a walking operation or a stepping operation on the belt, when a start indication signal indicating a start of assistance by the walking assistance apparatus is input to the controller according to an operation by an operator, the controller controls a motor of the walking assistance apparatus to make the walking trainee perform the walking operation or stepping operation, and the controller is adapted to maintain, after the start indication signal is input, an operation prohibition state in which the rotational operation of the belt is not started until the time that the detection unit detects the walking operation or the stepping operation a predetermined number of times and is adapted to cancel the operation prohibition state after the detection unit detects the walking operation or the stepping operation the predetermined number of times. the walking training system further comprises a detection unit that is adapted to detect whether the leg portion of the walking trainee on which the walking assistance apparatus has been mounted has performed a walking operation or a stepping operation on the belt, when a start indication signal indicating a start of assistance by the walking assistance apparatus is input to the controller according to an operation by an operator, the controller controls a motor of the walking assistance apparatus to make the walking trainee perform the walking operation or stepping operation, and the controller is adapted to maintain, after the start indication signal is input, an operation prohibition state in which the rotational operation of the belt is not started until the time that the detection unit detects the walking operation or the stepping operation a predetermined number of times and is adapted to cancel the operation prohibition state after the detection unit detects the walking operation or the stepping operation the predetermined number of times.