System for rehabilitating a walk comprising: - an active exoskeleton comprising a supporting structure for a right leg and a left leg, a bearing and moving structure of a femur of the patient rotating connected to the supporting structure, a bearing and moving structure of a tibia of the patient, with respect to the femur, rotating connected to the bearing and moving structure for a femur, a bearing and moving structure of a foot of the patient, with respect to the tibia, rotating connected to the bearing and moving structure of a tibia; - a weight supporting device which allows lifting or lowering the patient and the active exoskeleton associated thereto in order to place the patient in contact with the ground in a suitable position to allow walking exercises, said weight supporting device ending in a structure connected to means for supporting the exoskeleton and the patient; - moving means connected to the weight supporting device to allow its movement; - means for transmitting electric and pneumatic supplies and electric signals for managing, controlling, monitoring and diagnosing the system to the weight supporting device; - a managing system comprising a microprocessor to acquire and process data, and to manage a motion neuro-rehabilitating session; characterized in that it further comprises: - a suspension element connected on a side to the exoskeleton and to the patient through the means for supporting the exoskeleton, and connected on another side to a lifting band, and comprises a band collecting pulley actuated by actuating means, around which the lifting band is wound to change its length till its final locking in the desired position; and - a second device of a pneumatic type connected to a mobile pulley around which the lifting band is wound before getting to the band collecting pulley, which allows the free vertical movement of the patient starting from an initial position, with a constant weight relieving force, to allow a comfortable actuation for a patient. - an active exoskeleton comprising a supporting structure for a right leg and a left leg, a bearing and moving structure of a femur of the patient rotating connected to the supporting structure, a bearing and moving structure of a tibia of the patient, with respect to the femur, rotating connected to the bearing and moving structure for a femur, a bearing and moving structure of a foot of the patient, with respect to the tibia, rotating connected to the bearing and moving structure of a tibia; - a weight supporting device which allows lifting or lowering the patient and the active exoskeleton associated thereto in order to place the patient in contact with the ground in a suitable position to allow walking exercises, said weight supporting device ending in a structure connected to means for supporting the exoskeleton and the patient; - moving means connected to the weight supporting device to allow its movement; - means for transmitting electric and pneumatic supplies and electric signals for managing, controlling, monitoring and diagnosing the system to the weight supporting device; - a managing system comprising a microprocessor to acquire and process data, and to manage a motion neuro-rehabilitating session; characterized in that it further comprises: - a suspension element connected on a side to the exoskeleton and to the patient through the means for supporting the exoskeleton, and connected on another side to a lifting band, and comprises a band collecting pulley actuated by actuating means, around which the lifting band is wound to change its length till its final locking in the desired position; and - a second device of a pneumatic type connected to a mobile pulley around which the lifting band is wound before getting to the band collecting pulley, which allows the free vertical movement of the patient starting from an initial position, with a constant weight relieving force, to allow a comfortable actuation for a patient. - a suspension element connected on a side to the exoskeleton and to the patient through the means for supporting the exoskeleton, and connected on another side to a lifting band, and comprises a band collecting pulley actuated by actuating means, around which the lifting band is wound to change its length till its final locking in the desired position; and - a second device of a pneumatic type connected to a mobile pulley around which the lifting band is wound before getting to the band collecting pulley, which allows the free vertical movement of the patient starting from an initial position, with a constant weight relieving force, to allow a comfortable actuation for a patient.