The interlaminar shear stress plays a very important role in the damage of composite laminates. With higher interlaminar shear stress, delamination can easily occur on the composite interface. In order to calculate the interlaminar shear stress, a laminate theory, which accounts for both the interlaminar shear stress continuity and the transverse shear deformation, was presented in this study. Verification of the theory was performed by comparing the present theory with Pagano’s elasticity analysis. It was found that the present theory was able to give excellent results for both stresses and displacements. More importantly, the interlaminar shear stress can be presented directly from the constitutive equations instead of being recovered from the equilibrium equations.