Abstract: A simplified analysis model of geocell reinfocement incooperating subbase and subgrade’s shear effects is proposed to investigate the deformation behaviour of geocell reinforcement subject to pavement surface loads and to reveal the load transmission procedure from geocell reinforcement to subgrade. The Pasternak model, instead of the conventional Winkler model, is applied to describe the behavior of subbase layer and subgrade soil to account for stress spreading in these two layers. Geocell reinforcement is simplified as a finite-length beam embedded in ground to consider its bending stiffness. The differential equations governing pavement and geocell reinforcement’s deformations are solved using eigen decomposition technique, and a semi-analytical solution is obtained for geocell reforcement’s bending moment and shear force. The proposed model converges to the geocell reinforced pavement model with Winkler spring support when soil’s shear stiffness is reduced to sufficiently small. Compuation results show that soil’s shear stiffness is essential for accurately evaluating geocell reinforcement’s deformation. In addition, it’s found that geocell reinforcement has better performance when subgrade soil is weak.