Inclined retaining walls with slopes less than perpendicular are appropriate candidates in several engineering problems. Yet, to the knowledge of authors, only a few analytical solution for calculation of active earth pressure on such walls, which will be usually smaller than the same pressure on vertical ones, has been presented neither in research papers nor in design codes. Considering limit equilibrium concept in current research, a new formulation is proposed for determination of active earth pressure, angle of failure wedge and application point of resultant force for inclined walls. Necessary parameters are extracted assuming the pseudo-STATIC seismic coefficient to be valid in earthquake conditions. Moreover, based on Horizontal Slices Method (HSM) a new formulation is obtained for determining the characteristics of inclined walls in granular and or frictional cohesive soils. Findings of present analysis are then compared with results from other available methods in similar conditions and this way, the validity of proposed methods has been proved. Finally according to the results of this research, a simplified relation for considering the effect of slope in reduction of active earth pressure and change in failure wedge in inclined retaining walls has been proposed.