Abstract: The present study was undertaken to evaluate the humoral immune response directed against purified thioredoxin reductase (TrxR) protein during Plasmodium berghei infection. Thioredoxin reductase (TrxR; E.C. 1.8.1.9) was purified from rodent malaria parasite, Plasmodium berghei. TrxR induced humoral response in Balb/c mice immunized with parasite enzyme using saponin. Prechallenge sera gave ELISA titre of 1:512. IFA showed specificity of antimalarial antibody towards parasite. Immunization with TrxR provided partial protection in mice to P. berghei infection. Progression of P. berghei infection was delayed in TrxR immunized mice compared to normal controls.