Abstract: This paper explores the feasibility of the use of the methods of optimization for minimizing the safety factors in slope stability analysis. The routine precedure of finding the minmium safety factor includes comparisons of a number of potential slip surfaces which are basically selected by experience and random search. Low efficiency and unreliability are problems commonly encountered in profession.The methods of optimization allow a mathematically rigorous and reliable searching for minimum safety factor and its associated "critical slip surface". In this paper, the simplex, negative gradient and Davidon-Fletcher-Powell methods were employed. Test problems with a closed form solution and grid search solutions showed all the above mentioned methods were capable of providing accurate results. A case history analysis showed the feasibility of the methods. It is concluded that the methods of optimization provide powerful means for practitioners to facilitate their routine work in the calculation of the minimum safety factor.