The sensing positioning based on the signal strength in the indoor environment is the acknowledged and feasible method at present. It needs neither the complex hardware, nor the operation amount of high complexity. The consumptive cost is knockdown, and it is suitable to fit in to our living space. Although the noise in the environment or the multi-path effect in indoor would affect the stability of signal strength, but the sensing positioning based on the signal strength may avoid the interference of signal and forecast the location easily when signal strength is instable. In this paper, we propose an indoor-positioning system which based on the signal strength. The system integrates two phase work: Analysis of overlapping sensing area(Level 1) and Analysis of the direction movement and signal comparison(Level 2). The work of Level 1 is to search the overlapping areas, and identify the name to each overlapping area. Through the direction movement and comparison of signal strength, Level 2 would use the output of Level 1 to evaluate the positioning subtlety.