The aim of our research is to study the indicators of growth, development, immunomorphological alteration in the structural components of the spleen during correction of the body of hamsters under experimental loading with biologically active bee-keeping products (BABP), "Microvitum" preparation and their composite forms and without it. There was conducted comprehensive research to identify experience of growth, development, proliferation processes, differentiation, alteration of structural and functional components of the spleen in postnatal ontogenesis of hamsters and under experimental loading on the body with BABP, "Microvitum" preparation and their composite forms. The study found: the dynamics of change in the spleen weight, the absolute values of the average daily liveweight gain of hamsters in postnatal ontogenesis and on the background of introduced BABP (pollen, royal jelly), amino acid-mineral-vitamin preparation "Microvitum" and their composite forms to the diet; macro- and microstructure as well as immunomorphological alteration in the spleen of hamsters in postnatal ontogenesis and under the effect of BABP, "Microvitum" preparation and their composite forms; the relationship of the structural components of the spleen, T- and B-lymphocytes and their populations in the blood that condition immunobiological response of the harmster body in postnatal ontogenesis and ways to correct it with BABP, "Microvitum" preparation and their composite forms; the effect of the experimental loading on immunomorphological response of the spleen, the cellular and humoral component of the immune system and against the background of BABP, "Microvitum" and their composite forms introduced into the diet; ways to correct performance efficiency of hamsters, prevention of cannibalism and female hibernation with BABP, "Microvitum" and their composite forms.