Load/unload(L/UL) mechanism has been widely used in small form factor hard disk drive(SFF HDD) because it has many advantages necessary for portability. The ramp profile is one of the most dominant parameters which affect L/UL performance. In this paper, we focus on the design procedure of optimal ramp profile to improve the unloading performance. Firstly, the effects of the vertical unloading velocity are investigated by experiment. Secondly, designable ramp slopes are gained from the governing equations for the suspension and the slider. Finally, optimal ramp profile is designed and made through the ramp slopes, height and length. Therefore, this paper analyzes the dynamic characteristics for various unloading velocities, establishes the thesis for the optimal ramp profile design and verifies the unloading performance of the designed ramp profile with the experiment.