The paper conducted a research on the stability of Y 12 ' s Fermentation Product,with factors like heat,pH value,ultraviolet irradiation and time duration under normal temperature being considered.It is indicated in the experiments that Y12's fermentation product maintains stable under various degrees of heat,ultraviolet irradiations and acid environments,with the activity ratio keeping at 88.3% after showered by the 90℃ water for 30 minutes and 90.8% after irradiated by the ultraviolet for 7 hours;however,when situated under the alkaline en...