Abstract: To study whether the traditional Chinese herb medicine Houttuynia cordata can inhibit the proliferation of Newcastle disease virus, we applied chick embryo culture and hemagglutination test. The experiment was divided into four groups, the embryos in group Ⅰ were inoculated with the allantoic fluid containing virus and H. cordata extract, those in group Ⅱ were inoculated with the allantoic fluid containing virus and amantadine hydrochloride, those in group Ⅲ were inoculated with the allantoic fluid containing virus and normal saline mixture, and those in group Ⅳ were not inoculated with virus or drug. The results showed that the titer of group Ⅰ, Ⅱ, Ⅲ, and Ⅳ was 0, 5 log2, 9 log2, and 0, respectively, indicating that H. cordata extract had no toxic effect on chick embryo, and could completely inhibit the proliferation of Newcastle disease virus in chick embryo.