Abstract: A weight plate for physical fitness is disclosed including a plate body formed with a central through-bore for mounting on a bar to form a barbell set. The body is further formed with upper and lower half-donut shape shells and an annular core which fits tightly into both shells. The weight plate is not integrally cast therefore has high manufacturability and minimized manufacturing costs. Shells and core are integrated by sealing connection into a whole piece of plate having a smooth surface and an aesthetic appearance. The manufacture process is energy economizing and hardly causes pollution to the environment.