Abstract: The invention relates to a system for controlling the boom of a hydraulic crane, in particular, the crane being provided with at least one load sensor on the basis of which the speed of the boom is controlled so that the greatest permissible speed of the boom increases with decreasing load and correspondingly decreases with increasing load. The drawback of the known systems is that they do not in a satisfactory way consider the dynamic loads the crane is subjected to, wherefore their control properties are unsatisfactory. The problem is eliminated according to the invention so that in order to reduce the dynamic stresses exerted on the crane, the oil flow of the hydraulic actuating means is controlled by directly adjusting the movements of the valves of the actuating means on the basis of a speed instruction of the boom and of a load signal and by filtering such speed instructions which indicate valve movement speeds exceeding a predetermined value.