Abstract: The aim of the present study is to analyze the cellular and biochemical changes noticed in tasar silkworm larva (Antheraea mylitta D.) immunized with attenuated cytoplasmic polyhedrosis virus (AmCPV). The bioassay was carried out to confirm the no induction of disease in attenuated AmCPV inoculated larvae. Total Haemocytes count and Differential Haemocytes counts were carried out in healthy control, immunized and non immunized silkworm larvae at different time intervals. The hemolymph proteins were estimated in healthy control, immunized and non immunized silkworm larvae. The results confirm that, attenuated AmCPV provides protection against AmCPV infection for a short period (6 to 8 days). The mortality in immunized silkworms was reduced significantly as compared to non immunized inoculated control. The total haemocyte counts increased in haemolymph up to 8th day in immunized silkworms in comparison with non immunized inoculated control indicating the positive haemocyte mediated response in silkworm immunized with attenuated AmCPV. Similarly, differential haemocyte count was different in immunized silkworms from the inoculated control. The prohaemocyte, plasmatocytes and granulocytes were maximum in number whereas oenocytoids were minimum in number. The number of degenerated blood cells was increased in inoculated control up to 8th days of post inoculation. The hemolymph protein in immunized silkworms was significantly higher than non immunized control. The gradual increase 1st day to 8th day was observed in immunized silkworm. In non immunized inoculated control, the total hemolymph proteins have shown increasing trend from 1st to 5th day and decreasing from 6th day onwards.