A weight measurement system comprising: a wheel provided to a lower portion of a target measurement object to move the target measurement object for selectively carrying loads of varying sizes; and a weight measurement mechanism disposed between the wheel and the target measurement object to measure a weight of the target measurement object applied to the wheel, wherein the weight measurement mechanism comprises: an upper frame mounted on the lower portion of the target measurement object; a lower frame mounted on an upper portion of the wheel; an elastically deformable body positioned between the upper frame and the lower frame, the elastically deformable body having one end connected to the upper frame and an opposite end connected to the lower end; a deformation amount detection sensor provided on the elastically deformable body to detect an amount of elastic deformation of the elastically deformable body caused by the weight of the target measurement object, characterized in that a press-fit type fastening member (150, 152) is fastened to the one end of the elastically deformable body, and a first connection portion of the upper frame and connected to the opposite end of the elastically deformable body and a second connection portion of the lower frame; and wherein the press-fit type fastening member (150, 152) is screwed into the first connection portion and the second connection portion in a forced press-fitting manner, wherein the press-fit type fastening member (150, 152) is fastened through the first connection portion and the second connection portion, and wherein at least one of the upper frame and the lower frame is provided with an interference avoiding portion for avoiding interference with the press-fit type fastening member (150, 152). a wheel provided to a lower portion of a target measurement object to move the target measurement object for selectively carrying loads of varying sizes; and a weight measurement mechanism disposed between the wheel and the target measurement object to measure a weight of the target measurement object applied to the wheel, wherein the weight measurement mechanism comprises: an upper frame mounted on the lower portion of the target measurement object; a lower frame mounted on an upper portion of the wheel; an elastically deformable body positioned between the upper frame and the lower frame, the elastically deformable body having one end connected to the upper frame and an opposite end connected to the lower end; a deformation amount detection sensor provided on the elastically deformable body to detect an amount of elastic deformation of the elastically deformable body caused by the weight of the target measurement object, characterized in that a press-fit type fastening member (150, 152) is fastened to the one end of the elastically deformable body, and a first connection portion of the upper frame and connected to the opposite end of the elastically deformable body and a second connection portion of the lower frame; and wherein the press-fit type fastening member (150, 152) is screwed into the first connection portion and the second connection portion in a forced press-fitting manner, wherein the press-fit type fastening member (150, 152) is fastened through the first connection portion and the second connection portion, and wherein at least one of the upper frame and the lower frame is provided with an interference avoiding portion for avoiding interference with the press-fit type fastening member (150, 152). an upper frame mounted on the lower portion of the target measurement object; a lower frame mounted on an upper portion of the wheel; an elastically deformable body positioned between the upper frame and the lower frame, the elastically deformable body having one end connected to the upper frame and an opposite end connected to the lower end; a deformation amount detection sensor provided on the elastically deformable body to detect an amount of elastic deformation of the elastically deformable body caused by the weight of the target measurement object, characterized in that a press-fit type fastening member (150, 152) is fastened to the one end of the elastically deformable body, and a first connection portion of the upper frame and connected to the opposite end of the elastically deformable body and a second connection portion of the lower frame; and wherein the press-fit type fastening member (150, 152) is screwed into the first connection portion and the second connection portion in a forced press-fitting manner, wherein the press-fit type fastening member (150, 152) is fastened through the first connection portion and the second connection portion, and wherein at least one of the upper frame and the lower frame is provided with an interference avoiding portion for avoiding interference with the press-fit type fastening member (150, 152).