Abstract: The circle sliced method of slope stability analysis is widely employed in engineering practice. But two aspects of difficulties are faced by engineers in using of the method. The first is complex of calculation process, such as for every supposed slip circle, the boundary of slip surface, the width and height of each slice as well as the number of slices have to be defined before computation one by one; The second is uncertainty of potential slip surface, there are some methods of searching the most possible slip surface proposed, each of the them has advantage and shortage. In this paper, the authors make significant revision related to the two aspects. First of all, on the two dimensional section of the slope,the ground surface is regressed as linear equations properly while the slip surface is supposed as circle equation, then the accumulation plus could be substituted by integration in the equation of Fellenus method, the analyzed solution was derived finally. On the other wise, a method for searching the most possible slip surface is suggested. We supposed the coordinates of top point and thrust point of slip surface as known, then the factor of safety varied with curvature of the circle through the two points. We could easily convert the factor of safety to a function of a parameter of length t by aiding of geometric method. Supposed the first derivative of the function equal zero, we could solve the equation to get the value of t . Accordingly the minimum factor of safety and the correspondent radius of slip circle could be defined. As we supposed differential position of top point and thrust point of slip surface, the most minimum factor of safety and the correspondent slip circle could be defined.