The formation conditions morphology and machanical properties of the CuCo_2Be alloy of widmanstatten structure were studied in this paper. The results show that the widrmanstatten structure in the form of needle CoBe phase in CuCO_2Be alloy under a given condition and has a strict orientation with the matrix. The widmanstatten structure, the needle CoBe phase in CuCo_2Be alloy would be spheroidized and coarsenned, annealing for long time at high temperature after resulting in the change of mechanical properties.