A fan blade for heat sink fans is provided. The fan blade includes a wheel hub and a plurality of blades which is disposed around the rim of the wheel hub. The surfaces of the blade fans are designed with protruding or recessing inhibiting part. The flow rate on the blade surfaces is made unsteady by the inhibiting part as the airflow is flowing by to form a constant air flow impact and generate a boundary layer on the blades effectively. The effective second order distribution of the pressure rise is formed, and the effective working area of the fan is expanded. The improvement increases the static pressure and lowers the noise.