For the purpose of exploring the stability of producing exopolysaccharides (EPS) for Streptococcus thermophile, 3 different strains (ST-5P, ST-7P, ST-134P) fermented in the exopolysaccharides selection medium for 30 periods (24 hours for each period) multiplication. The results showed that the proliferation and acid production of ST-5P, ST-7P and ST-134P were stable. The stability of producing EPS among these three strains was different. The EPS production of ST-7P was significantly more stable than those of ST-5P and ST-134P. The correlation analysis in SPSS showed that there was no direct correlation between EPS concentration and viable cell numbers or pH value.