Abstract: ObjectiveEffects of porcine reproductive and respiratory syndrome virus(PRRSV) positive serum accli-mation and vaccine immunization on immune antibody level and reproductive performance of gilts were analyzed, in order to provide reference for large-scale farms to select the proper immunity method to control porcine reproductive and respira-tory syndrome(PRRS). MethodGilts of 90 days were immunized with serum acclimation and vaccine immunization re-spectively. Blood samples were obtained from vena cava anterior to detect antibody level. Meanwhile, indexes of reproduc-tive performance were measured, including conception rate of the firstborn, delivery rate, litter size, number born alive of litter, weak piglet rate, stillbirth rate, deformity and mummy rate of gilts. ResultSerum antibody positive rates of serum domestication group and vaccine immunization group reached 100.00% and 99.30% respectively. Antibody level dispersion of vaccine immunization group was low and its antibody level was concentrated. Conception rate of the firstborn(96.79% vs 97.11%), delivery rate(88.55% vs 88.96%), litter size(11.26 vs 11.41), number born alive of litter(10.3 vs 10.5), weak piglet rate(3.61% vs 3.32%), stillbirth rate(2.96% vs 2.99%), deformity and mummy rate(4.35% vs 4.13%) of gilts in serum domestication group and vaccine immunization group were close. The difference between the two groups was in-significant(P>0.05). The performances of the two groups were both better than that of control. ConclusionIt is suitable way to immune pig with serum acclimation to prevent and control PRRSV when there is only a serotype PPRSV prevalent in pig farm. This vaccine method not only enhances the reproduction performance of gilts, but also costs less and operates easily.