The purpose of this study was to test the effectiveness of source virus strain for the manufacture of the inactivated SARS virus vaccine, and establish an experimental method and preliminary standard for potency evaluation. Mice were divided into groups for being immunized with corresponding serially diluted experimental SARS virus inactivated vaccine. And the rabbits were immunized with undiluted vaccine. Challenge assay was conducted with a heterologous SARS virus. And the neutralization antibody was determined with plaque reduction neutralization test (PRNT), to which the neutralization antibody in the convalescent serum of SARS patients was compared. The experimental vaccine viral strains were proved to be suitable for manufacturing the vaccine. Mice immunized by vaccines of serial dilutions were able to elicit neutralizing antibody. The antibody titer from mice immunized with the undiluted vaccine could reach up to 1∶495.2, while those of rabbits immunized with the undiluted vaccine could reach a GMT of 55.0-79.9. The capability of the antibody to neutralize the virus from Guangdong is more efficient than that from Beijing. The GMT of neutralizing antibody in SARS convalescents living in south and north China ranged from 50.12 to 54.95, and the titers of convalescents from north China were higher than those from south China. Mice and rabbits used as the model for evaluation of potency are of sensitivity, and the test is of reproducibility. The candidate challenge viral strains showed a relatively consistent effect on evaluating antibodies produced by various batches and different vaccine-source strains, hence they can be used to evaluate potency of the vaccine. The method for testing the vaccine potency and the evaluation standard was established preliminarily. The purpose of this study was to test the effectiveness of source virus strain for the manufacture of the inactivated SARS virus vaccine, and establish an experimental method and preliminary standard for potency evaluation. Mice were divided into groups for being immunized with corresponding serially diluted experimental SARS And the rabbits were immunized with undiluted vaccine. And the neutralization antibody was determined with plaque reduction neutralization test (PRNT), to which the neutralization antibody in the convalescent serum of SARS patients was compared. The experimental vaccine viral strains were proved to be suitable for manufacturing the vaccine. Mice immunized by vaccines of serial dilutions were able to elicit neutralizing antibody. The antibody titer from mice immunized with the undiluted vaccine could reach up to 1: 495.2, while those of rabbits immunized with the undiluted va ccine could reach a GMT of 55.0-79.9. The capability of the antibody to neutralize the virus from Guangdong is more efficient than that from Beijing. The GMT of neutralizing antibody in SARS convalescents living in south and north China ranged from 50.12 to 54.95, and the titers of convalescents from north China were higher than those from south China. Mice and rabbits used as the model for evaluation of potency are of sensitivity, and the test is of reproducibility. The candidate challenge viral strains showed a relatively consistent onctor antibodies produced by various batches and different vaccine-source strains, hence they can be used to evaluate potency of the vaccine. The method for testing the vaccine potency and the evaluation standard was established preliminarily.