In the case of axial fans, there are more complex mechanism involved in transferring the energy from the fan blades to a flowing fluid and generating aerodynamic noise due to the blade tip vortex. In this paper, the effects of blade tip shape on vortex structure and aerodynamic noise of axial fans which are used as a cooling fan in an outdoor unit of air-conditioners are numerically and experimentally investigated. Two types of axial fans are considered: one is with blade tip-rake and the other is without blade tip-rake. The blade tip-rake in introduced in the axial fan to reduce the tip vortex as the wing fence does in the airplane. First, the flow field around the fans was predicted by solving the three-dimensional unsteady compressible RANS equations using computational fluid dynamics techniques. Then, the validity of the numerical results are confirmed by comparing the predicted flow rates with the measure ones. The characteristics of flow field driven by the fans with and without blade tip rake are analyzed in detail, especially with an emphasis on the coherent vortex structure. Finally, the aerodynamic noise of axial fans are characterized according to the vortex structure related to blade tip shape.