There is no clear criterion yet for evaluating wipers based on performances of wiping raindrops and visibility in forward view. In the visibility evaluation, it is important to examine spatial frequency and contrast of forward view. In this paper, we propose a new method for evaluating wiper performances based on visibility in forward view. Spatial frequency and contrast of image in the footage which were affected by the raindrops are calculated based on them of background board which were printed stripe patterns. The variations with time of power spectrum and decreased contrast are synchronized with the motion of the wiper for the all experimental cases. These results show that to evaluate wiping performance is possible by the method which we proposed.