Abstract: On the basis of the measured values of lateral displacements of some engineering, the limitation of lateral displacement measured by inclinometers and side pilings is analyzed. The results show that the twisting angle of an aluminous alloy pipe is rather little, while the twisting problem of a plastic pipe is serious, that, when the deformation of an inclinometer pipe reaches an extreme state, the lateral displacement under the extreme deformation location can not be gotten conveniently any more, and that, moreover, the inclinometer cannot get the compatibility of deformation with soil, for it is fixed with both ends by hard soil and has a greater stiffness than soil. So, the valueof lateral displacement obtained from the inclinometer is inaccurate. Therefore, the technique of measuring lateral displacement should be improved, the design methodology of gauge head with wheel guiding in the inclinometer pipe modified, and the number of uncertain factors influencing the testing results abated. 