Abstract: In this paper, considering the retaining structure—L type retaining wall used in section from Golmud to Lhasa, Qinghai-Tibet railway,we test the earth pressure or frost-heave in a frost-thaw cycle for one year,and we study several different analytic models of earth pressures and frost-heave.Compared with site test and theoetical analysis, we know that the actual earth pressure is large than the designed earth pressure.Then a revised analytic model of earth pressure is put forward,which could consider other possible force outside slide medge.This model could give a reference to some similar engineering projects.