Abstract: Based on the sliding plane hypothesis of Coulumb earth pressure theory,the analytical solution of active earth pressure acting on retaining walls was deduced by using the thin layer element method,considering the complicated circumstances that the backfill was soil with cohesion and friction angle,the back of retaining walls and the ground surface of backfill were both inclined,the frictional and adhesive forces existed on interface between retaining walls and backfill,the tension crack appeared at the shallow part of backfill and even continuous surcharge load acted on the ground surface of backfill.The analytical solution was applicable to the complicated conditions of cohesive soils and non-cohesive soils.Meanwhile it was proven that the prevailing classical Rankine and Coulumb earth pressures were two special examples simplified under the condition of their assumptions,respectively.It was shown by calculations of 3 engineering cases that the active earth pressure distributions computed by the deduced formula agreed well with the measured non-linear ones,indicating that the analytical solution was reliable to be used to calculate the active earth pressure in engineering projects.