Abstract: Based on the characteristics of high vertical bearing capacity and low horizontal bearing capacity of the cement soil, field tests on cement-soil piles and reinforced cement-soil piles which are arranged cylindrical fiber glass geogrid under lateral load are carried out. According to change of the lateral load-displacement, horizontal force-displacement gradient and horizontal force-inclination of pile head, the horizontal bearing performance of cement-soil piles and the reinforcement effect on the horizontal load-bearing characteristics are discussed. The results show that single pile and double-row piles which arranged cylindrical fiber glass geogrid are elastic piles. Geogrid makes horizontal displacement continue to increase with horizontal force at a constant rate and there is no critical load inflection point. Double-row piles which are arranged cylindrical fiber glass geogrid are significantly improved in displacement control respect, but its contribution to the improvement of horizontal bearing capacity is limited. Failure modes of a single pile and double-row piles are direct shear failure under the surface loading position. It is concluded that the horizontal bearing capacity of piles in the shear failure mode can be improved by these approaches: reasonable fabric reinforcement, increase of cement content to achieve compatible pile-soil deformation and increase of number of pile rows to increase shear area. Further researches on the georgid-reinforcement and the engineering application are still needed.