This paper introduces the LANDMARC algorithm and VIRE algorithm that is based on RFID in indoor location. And after analyzing the drawbacks of VIRE, an improved algorithm is proposed on combining of the Newton interpolation and the positioning results correction which use historical results. The improved algorithm applies Newton interpolation to adapt to nonlinear characteristics in the solution model and uses the historical data of location label as a reference, constantly revising measurements to reduce the influence of interference on positioning precision. The experiment in complex environments proves that the location precision of improved algorithm is significantly higher than VIRE algorithm.