One of the main stages of beekeeping is stimulating the early develop-ment of bee colonies in the spring. Of particular relevance is the search for new bioregu-lators that can stimulate the development and increase the productivity of bee colonies. The purpose of the research is to determine the influence of the CobalStev biostimulator admin-istered in bee food on the growth, development and productivity of bee families. It was revealed that the optimal dose of CobalStev biostimulator in bee feed, in the spring period, in the absence of maintenance honey collection, is 2.0 ml/L of sugar syrup. The use of the method of feeding bees in the spring period in the absence of maintenance honey collection, when the reserves in the nest are reduced, with a mixture of sugar syrup 1:1 in the amount of 1.0 L of the mixture for a family of bees, over every 7 days, starting in April until the main harvest, increases the strength of bee colonies by 7.34%, the number of hatched broods by 16.81% and honey production by 9.77%