Technologies to identify people and determine their positions are developing rapidly day by day. Many means exist to estimate a person’s position. Mainly, wireless sensors are used. Nevertheless wireless sensors have problems in accuracy. Because of multipath problem, wireless sensors cannot actually measure one’s position as the level of their specifications. This causes some fatal problems to estimate an area where person is. In this paper, we present a way to improve position information by filtering data which was obtained by a wireless location awareness system. We also show designed filter which is based on particle filter is effective by simulations and experiments.