Available evidence indicated that the deficiency of a specific nutrient in the diets adversely affect antibody production from a mild to severe degree. Studies of the effects of diet partially deficient in various essential nutrients on antibody response is meagre. Twelve groups of weanling rats were fed with diets prepared by diluting the basal diet with 0 to 75 percent sucrose for 46 days and their antibody response was measured on the 28th, 40th and 46th day using Salmonella pullorum as the anti gen. The rats fed the diet containing 75 percent sucrose and 25 percent basal diet had mean antibody titer of 15 as compared to 143 for their controls which were fed 100 percent basal diet. The antibody titer decreased as the basal diet was diluted with increasing amounts: of sucrose. Comparison of antibody titer with total serum proteirus, serum vitamin A, hemoglobin, and hematocrit showed that a multiple deficiency in the diet depresses antibody response much more severely than total serum proteins, serum vitamin A, hemoglobin or hematocrit . Rats which had coprophagy prevented had slightly lower food intake, growth rate, antibody response than rats allowed coprophagy.