A locating system for indoors has been tried to develop by using WLAN systems (protocol number: IEEE 802.11). Wireless modems using IEEE 802.11 protocol installed all around 4 corners of corridor were used as RF transmitters as well as laptop computer was used as RF receiver. A computer software generated by EMUMAM software group was used in order to calculate RSS, and 672 different measurement data were collected. Each location measurement was repeated by 7 times. 100% location success rate is achieved within the ±10% deviation and ±5% deviation in exact location is achieved with 75% success.