GPS (Global Position System) is a very popular location technology, but because the satellite signals may easily be obscured by buildings, GPS is not suitable for use in indoor location. The LANDMARC system is radio frequency identification (RFID) based location system and has attracted great attention recently. In our implementation of the LANDMARC system, we have observed that some unusual large errors occur in the traditional LANDMARC. Thus, in this study, we proposed ways of resolving these problems.