Abstract: The biological characteristics of five kinds of bacteria including Bacillus subtilis, Lactobaeillus acidophilus, Enteracoecus, brewers＇ yeast, Saccharomyces cerevisiae were studied in simulative rumen environment. The results showed that the five strains were all safe, no antagonism between each other, resistant to acid, alkali and bile salts, and antagonistic to common pathogens, which agree well with the preparation requirements of ruminant compound probioties. After the fermentation medium and fermentation parameters of the five kinds of bacteria were studied and optimized, a novel production technique of compound probioties was developed.