Based on the strength reduction method in slope stability analysis

two-dimensional analysis is promoted to three-dimensional slope analysis; and its definition way of safety factor

yield rule and destruction criterion are researched. The three-dimensional finite element analysis conform to the reality more than traditional three-dimensional limit equilibrium method and two-dimensional finite element analysis

and it may simulate the solution of practical project well by example. Also

some influential factors in two-dimensional and three dimensional analyses are discussed; and some conclusions are drawn as follows: the computed result by using Mohr inscribed circle yield rule is less than that by using Mohr circumcircle yield rule in the same model. The lateral boundary constraint condition and the ratio of length to height have well influence on the computed result; the safety factor will increase greatly when lateral is restrained completely

but reduce gradually along with the increase of ratio of length to height.