Ballistic tests were performed to investigate the anti-penetration properties of ultra-high molecular weight polyethylene fiber-reinforced laminated plates (UFRP) against high-speed cubic fragments. Energy absorption performances were compared among these fiber-reinforced laminated plates with the four different area densities of 7.11, 15.4, 20.6 and 30.8 kg/m2. Experimental results show that the relations of ballistic limit and area density for the thin UFRP are different from those for the thick ones. Vertical strips on the obverse sides of the thin UFRP and horizontal strips on their rear sides can be observed, but no trips can be seen from the thick UFRP. It is required to consider effects of stamp deformation of the fragments on energy absorption and deformation modes of the thick UFRP impacted by high-speed fragments.