This paper expounded that GCHV-841 sifted is cultured with adaptability in cell line(PSF) from the fibroblast cell of grass carp(Ctenopha-ryngoho ldella)snout tissue, attenuated domostication, preparation ofattenuated live vaccille obtailled through cell cultUre,observation on innoeuity,determination of percent relative protection with difforent dilutions and dosages,and test of storage.GCHV-841 has been domesticated continuously for 53 generations and has been attenuated. The attenuated live vaccine prepared with generation 53-59 is safe for use.The percent relativg protection of vaccine is above85%, when it was injected to grass carp with vaccine of diluted 10-10⁴ tiniesand dosage 0. 1-0. 3ml/ind. The suitable concentration and dosage are diluted 10² times and 0. 2ml/ind. It is suitable to store the freeze-dried vaecine below 4℃.The comparatively suitable storage time is 6 months in 4℃ or 18 months in - 20℃.