The invention relates to an exercising device, and particularly relates to an arm exercising device for physical exercise. The arm exercising device for physical exercise meets the demand of exercising people and facilitates exercising. According to the technical scheme, the device comprises a seat, a supporting plate, a moving device, storing seats, iron blocks, a supporting rod, a first slidingsleeve, etc., wherein an exercising difficulty adjusting moving device is mounted at the lower part of the seat; the left side surface of a supporting plate is connected to the moving device; four storing seats are arranged and are mounted on the top part of the supporting plate; the iron blocks which are n-shaped and different in weight are stored in the storing seats; first through holes for guiding are formed in the bottom parts of the storing seats; and four second through holes are formed in the supporting plate. According to the device, the arm exercising difficulty can be adjusted through the moving device, so that exercising people can do arm exercise at different difficulty level conveniently, and moreover, the demands of different exercising people can be met.