In this paper, a combined spline finite strip and state space approach is introduced to obtain three-dimensional solutions of laminated composite plates with various boundary conditions. The spline finite strip method is used to present inplane displacement and stress components, while the through-thickness components are obtained by using the method of state equation. The new method provides results that show good agreement with available benchmark problems having different material compositions, thickness and boundary conditions. The new method provides a three-dimensional solution for laminated plates, while the advantages of using the traditional spline finite strip method are fully taken. This solution also yields a continuous transverse stress field across material interfaces that normally are not achievable by other numerical modelling of laminates, such as the traditional finite element method.