Abstract: On the basis of the object and problems in researches on earth pressure of unsaturated intact loess, field tests are performed, in which one end of a tie bar is anchored in a pile that is at the stable region of a slope, and the other end is anchored in the free force of the slope by steel pate and screw. The height of the vertically cut slope is 14.5 m. Slope cutting is performed as segmentation from top to bottom of the undisturbed slope. The tension of the tie bar is measured so as to calculate the earth pressure on the steel plate. The test results indicat that the acting position of the maximum earth pressure strength is at one-third of the height of the vertically cut slope. When the point of application is higher than one-third of the height of the vertically cut slope, the distribution of earth pressure exhibits an approximate triangle, and when the point of application is lower than one-third of the height of the vertically cut slope, the earth pressure strength decreases as the point of height increases. The test results are obviously different from the Rankine’s and Coulomb’s classical theories for earth pressure.