Abstract: The matrix of the composite, Al/Al-A₃Ni has a good thermal stability, so the fracture work and the fractal dimension can be changed by changing the tensile temperature.The fractal dimension was measured by means of fracture profile method(FPM).The results indicate that the fractal dimension can be divided into three parts,and the each part of the fractal dimension correspond to a certain part of the microstructure.The relationship between the fracture work and the fractal dimension was also studied in the paper.