Abstract: For evaluation and study the vaccine against HFRS of Mongolian gerbils kidney(MGK) and Infant muose brain(IMB) on the targets of safety,serological and immunological efficacies,antibody-dependant enforcement(ADE) and immune strategy.In 1994 the inoculation group andcontrol group for the 2 kinds of vaccine were established in some high case-rate areas of Shaanxi Province,then the researched targets-were inspected for the following 4 years.The inoculation reactions of 2 kinds of vaccine were mild in extent and low in rate.At the times after basic inoculation of 2 weeks 1 yearCjust before the enhancement inoculation),1 year(2 weeks after enhancement inoculation),2 year.3 year 4 year the positive rates of neutralizing antibody of IMB and MGK vaccines were 78 57%,7.84%,52.94%,45%,10.00%,23.53% and 73.08%,27.45%,76.47%,40 00%,30.00%,29.41%.The preventive rates of IMB and MGK vaccines at each year were 95.13%,100 00%,87.60%,80 13% and 98.23%,94.45%,100.00%,74.06%.ADE was not found.2 kinds of vaccine were safe had no ADE.The positive rates of neutralizing antibody presented a tendency of decline year by year.The preventive rates were above 87% in first 3 years but decreased to some extent at 4th year.The suitable periods for vaccine inoculation in Shaanxi Province were in April to May or September to October,the age group for taken vaccine should be 10 years and older.