Abstract: Wireless positioning technologies and location-based services have gained much attention and development over the past several years. As a compensate to global positioning system (GPS), Wi-Fi positioning, Wi-Fi fingerprinting in particular, which makes use of widely-deployed wireless LANs, has been accepted as a common solution to indoor positioning. Due to the interference of various factors during the signal transmission, positioning accuracy is often degraded and unstable. The estimation of the room and the floor that the user is in is often wrong. This paper proposes to use a history-based Wi-Fi fingerprinting algorithm in combination with the interior structure of the building for indoor positioning. Experiments show that the enhanced algorithm is able to improve the accuracy and stability of Wi-Fi fingerprinting and reduce wrong estimations of rooms and floors. Furthermore, this paper proposes a multi-floor handling algorithm which is able to reduce wrong estimations of floors.