Abstract: This paper presents a study on the precision and reliability of landslide deformation monitoring with GPS-RTK technology.Some monitoring points were set on the landslide body.The GPS RTK technology,the three-dimension surveying technology by total station and the GPS single epoch positioning technology were used to monitor the deformation process from stable state to the failure of the landslide in real time. The results are further combined with large physical model experiment of one kind of landslides.The processing and analysis on the monitored data of the landslide have resulted in the technique parameters about reliability and precision of landslide deformation monitoring with the RTK technology.That is,the precision of plane and height from RTK can be controlled within 15mm and 20mm respectively,under the conditions that there are more than seven satellites observed synchronous and the data link can work normally.The experimental results indicate that the GPS-RTK technology can be used to monitor the dynamic and real time deformation of this type of landslides when the observation conditions are favorable.