According to the population statistics by the Ministry of the Interior, the population of elder came to 7% in 1993 ,which already became the ?Ageing Society? called by W.H.O. (World Health Organization). In the end of 2000, there were 1,960,872 people over 65 years old which occupied 8.84% of all the population in Taiwan (MINISTRY Of INTERIOR, 2000), there will increase to 14% in 2020 and 30% in 2030 approximately. It shows that a large amount of elderly people won't be taken care by their children, and also have no support from home resources for their retiring lives. This research discusses how to locate the elderly people by the use Wireless Local Area Network Location Technology .It change the custom of elderly in daily life. We use IEEE 802.11(WIFI) wireless networking technology. Ekahau Site Survery 2.2 (ESS2.2) is simulated to set the optimal position of AP, and Ekahau Positioning EngineTM 3.1 (EPE 3.1) is used to develop a set of software applying for Home-Care.