Equine herpesvirus 1 (EHV-1), infections is found in horse populaces worldwide and cause a febrile respiratory ailment every year among foals in zones with concentrated steed populaces, the result of infection is dictated by viral strain, resistant, pregnancy status and potentially age, disease of pregnant mares with EHV-1, may abort after weeks to months by clinical or subclinical infection. Treatment of viral infection in animals it appears to be exceptionally troublesome and require a considerable measure of cost, in the present investigation, we used a steroidal saponin compound from dry roots of shallot, the infection rate of EHV-1 in vitro was detected by neutralization test and flowcytometric analysis, the result of infection rate was decreased after 24 hour by 55.7 - 59.2 % when added saponin with concentration of 50µg-100µg, this natural compound may be used as effective materials for treatment animals against viral infection.