Wireless sensor networks (WSNs) are often deployed by random bestrewing (airplane bestrewing for example). A majority of nodes cannot obtain their coordinate beforehand. Therefore, how to obtain the position information of unknown nodes, which is called localization problem, has become a hot topic in WSN. Without position information, WSN cannot work properly. Global Position System (GPS) is the most extensive and mature position system at present. But because the nodes usually have the shortcoming of high expenditure, large volume, high cost and require settled basal establishment, therefore, the GPS is inapplicable for the low-cost selfconfigure sensor networks, and also it is impossible to install GPS for each sensor node. In this paper, we will study localization mechanisms (which is not based on GPS) used in WSN, and will test the effectiveness of using MUSIC algorithm in determining the signal arrival angel depending on the SDMA- technology and ESPAR antenna.