Wheel loader is one of the construction machinery capable of variety of tasks and the demand on functional diversity and structural reliability is growing. As a study on the optimal shape design of front axle for wheel loader through the design of experiments, this paper assessed the design parameters affecting the maximum stress. As a result, a value of 126.77 MPa of minimum stress was obtained, and optimal factors showed the values of w = 100.0 mm, ${ heta}=40^{circ}$ and R = 118 mm. It showed an accuracy of 98.7% compared with the structural analysis.