Abstract: In order to obtain the deflection and bending analytical solution about concrete rectangular thin plate (RTP) of three clamped sides and one free side, in this paper, based on the small deflection plate theory and superposition principle, considering temperature variation which is perpendicular to surface, the RTP of three clamped sides and one free side under temperature disparity is regarded as under the superposition of temperature disparity and the bending moment with three adjacent sides. Firstly, by supposing deflection function which has undetermined parameter at free side, and adopting Levy method, the closed solution about the RTP under free boundary constraints is obtained;Secondly, the closed solution under temperature disparity is obtained;Thirdly, using the solution of RTP with four simply supported sides under the bending moment on three adjacent sides, the solution of RTP with three simply supported sides and one free side under the bending moment on three adjacent sides is obtained;Finally, the deflection and bending analytical solution about RTP of three clamped sides and one free side under temperature disparity is acquired adopting the superposition principle, and calculation coefficient table about concrete RTP of three clamped sides and one free side under temperature disparity is obtained using MATLAB. And so a theory calculation base about concrete RTP with three clamped sides and one side free under temperature disparity in engineering structure is provided for engineering design.