Piezoelectric energy harvesting generated by ground reaction force of pedestrian is one of the human-powered energy systems and grows rapidly. Under the circumstances, mechanical issues and the problems about planning and design, which have never been studied, should be treated simultaneously to develop the efficiency of the new technology. Therefore, this paper conducts an experimental study on where to install and how much energy can be generated by the piezoelectric generator on stairs. Firstly, the distribution of pedestrian walking on 3 types-straight, return and spiral stairs-of stairs are analyzed. The number of pedestrians are estimated by calculating the number of steps by a zone which is divided into same size of $30cm{ imes}30cm$. As a result, it shows a large distribution in the middle of the stairs in case of straight and spiral stairs. In case of the return stairs, it shows a large distribution not in the middle, but inside of the stairs. After observing pedestrian walking characteristics by the walking distribution, we estimate the electricity generation by the number of the devices installed on the stairs. According to the estimation, the less devices installed, the less total generation made. However, the generation by a device grows 1.6~1.9 times when assumed that only one device is installed on the most high density zone in scenario 4 comparing to scenario 1.