In the present paper , the conditions for the induction of interferon from grass carp , Ctenopharyngodon idellus were described .The results showed that the interferon of grass carp could be induced rapidly following experimental infection with the viruses .After the virus being inoculated for 24 hours , the interferon activity in serum sample exhibited obviously .Maximum yields of serum interferon were observed after the virus being inoculated for 3 days .The production of grass carp interferon was influenced by the environmental temperature , different viral inducers , virus dosages as well as the nutrient conditions of the fish .The induction of grass carp interferon was shown to be temperature-dependant .Titers of interferon induced at 25 ℃ was higher than that at 15 ℃ and 8 ℃. Among seven viral inducers , the interferon inducing ability of six RNA viruses was higher than that of DNA virus .And the GCHV which was of the genome of dsRNA possessed the highest interferoninducing ability .High virus dosages and good nutrient conditions for the fish were advantageous to the production of interferon .The production of grass carp interferon could also be enhanced by priming the fish with interferon or pre-inducing the fish with inactivated GCHV for appropriate time .However , the influence of virus infectious activity and the ages of fish on the induction of interferon had not been observed .