Slope roadbed stability in permafrost regions of Qinghai-Tibet Railway is a potential threat to long-term operation. In evaluating slope roadbed stability, thermal stability is of first importance. Through measuring ground temperature at Anduo section for three years, ground temperature changes and the changing trend in the next 50 years have been analyzed. From the research, the conclusions are as follows: ① filling railway embankment makes permafrost temperature field redistribute; asymmetry of slope direction and geometric asymmetry make ground temperature field asymmetric; ② filling railway embankment causes artificial permafrost table of roadbed change and show asymmetric, which changes original thermal balance...