Abstract: The purpose was to observe the safety,immunity,middle-term epidemiological efficacy of Type I Inactivated Vaccines against HFRS prepared from tissue of Monqolian gerbils kidney.ELISA IFA were used in testing specific antibody in sera.MCPENT was used in testing neutralization antibody.HI was used in assaying serological type.It was proved safe that the population who lived in the wild rodent epidemic area were inoculated vaccines.The seroconversion rate of HFRS.V.IgG antibody was 96 43%.GMT = 35.18(42 days after primary immunization).The former dropped apparently on 180th day.The rate of seroconversion was 100% (two weeks after reinforced immunization) The 36.36% of them were still tested HFRS.V.IgG antibody (1:10) on 1200th day The seroconversion rate of specific antibody by MCPENT was less than by IFA.The specific reminiscence reaction was existed among the immunizated population.The epidemi-oloigcal effect of middle-term.The incidence rate of inoculation group was 2.35/100 000 and that of the control group was 42.93/100 000.The protection rate of the vaccine was94.53%.The result was showed safe that the population of epidemic area were inoculated the Type I vaccine gainst HFRS.The epidemiological effect of middle-term was satisfied.