An analytical procedure has been developed to fulfill the need for a technical support of the design of well balanced ROPS. The procedure is incorporated in a computer program referred to as SAPROPS by its acronym. SAPROPS performs elastic-plastic,non-linear analyses of space frames by the direct stiffness method.Examples are given to demonstrate effective applications of the program to the design of ROPS for agricultural and earth-moving vehicles. Good correlations between the computed results and the experimental data are shown. A possible enhancement of the analytical procedure is also discussed.