A novel refractory Hf25Nb25Ti25Zr25 high entropy alloy (HEA) with single body centered cubic (BCC) structure was prepared by copper mold cast method. This HEA still holds the single BCC phase even after furnace cooling from homogenization at 1573K for 6h. The fracture strength and plastic strain of this HEA reach about 969MPa and 14.9%, respectively. There is significant work hardening effect in this HEA, which is considered as resulting from the movement and multiplication of dislocations. •A novel refractory Hf25Nb25Ti25Zr25 high entropy alloy was prepared by conventional arc-melting method.•The prepared high entropy alloy possesses single body centered cubic phase and high thermal stability.•The prepared high entropy alloy exhibit tensile fracture strength up to 969MPa.•The prepared high entropy alloy exhibit tensile plastic strain of 14.9%.•The fracture manner and strengthen mechanism were investigated.