The aim of the research was to study morpho-functional state of some organs of digestive and immune system in chickens with Hepatitis E virus. The diagnosis BLSD (syndrome of "big liver and spleen" was made as a result of virological studies in Clinic for Avian, Reptile and Fish Medicine (Hun-gary). Paraffin sections of the stomach and spleen were stained for observational studies with hema-toxylin and eosin, according to Van Gison, Mallory, Weygert, Brache on plasma cells, put the SHIC-reaction for the detection of carbohydrate-containing biopolymers, and stained using Jones a. Reid (Jones a.Read, 1973) for the differentiation of acidic and neutral carbohydrate-containing biopol-ymers. To isolate subpopulations of lymphoid cells lectins peanut, soybean and snail labeled with horseradish peroxidase were used. The autopsy revealed spleno- and hepatomegalia. Histological result of research showed that in glandular stomach of the chickens infiltration by lymphocytes and plasmatization mucosa, acidic secret in the cavity of the superficial glands, desquamation of the epi-thelium of the wall of the superficial glands, fatty degeneration of the muscularis tunica were ob-served. In the spleen there were apoptosis of lym-phocytes, amyloidosis and necrosis of lymphoid nodules, active plasmatization red pulp. In the area of finding the lymphoid nodules of white pulp, foci of necrosis took place. Profound changes of blood vessel walls, - endothelial desquamation, homoge-nization and partial lysis media were observed. Thus, in hepatitis E virus in the glandular stomach of the chickens there were infiltration of lympho-cytes and plasmatization mucosa, acidic secret in the cavity of the superficial glands, desquamation of the epithelium of the wall of the superficial glands, fatty degeneration of the muscularis tunica. In the spleen the apoptosis of lymphocytes, amy-loidosis and necrosis of lymphoid nodules, active plasmatization red pulp, homogenization and partial lysis of blood vessel wall were revealed.