Boron carbide (B₄C) is the third hardest materials in the nature following the diamond and cubic boron nitride. However, due to bulk B₄C is hard to be synthesized and the fracture toughness of B₄C is very low, B₄C can not be widely used as superhard material. In this work, High-quality bulk B₄C was successfully prepared at high pressure and high temperature. It is worth nothing that the as-synthesized B₄C possess high hardness and high fracture toughness （4.51 MPa?m^1/2）which are superior to single crystal. The high Vickers hardness and high fracture toughness of B₄C are attributeed to its high densification and nanosheet structure.