Abstract: This paper describes the mathmatical model of the strain of grouting rod according to measuring data in situ. The stress and displacement of the grouting rod can be calculated by this model. The radial stress of the surrounding rock can be solved by means of Mohr-Coulomb yield condition if the reaction of the rod on the surrounding rock is assumed to be symmetric radial action. The deformations of the grouting rod support are determined according to the conventional deformation formula of the supporting structure consider the peripheric deformation of the surounding rock is non-uniform but symmetric to axis by the deformation of grouting rod being consistent with that of surrounding rock, the basic equations of grouting rod support was put for-word.