Abstract: The Non-Ionic Surfactant (NIS) was evaluated for its ability to influence rumen fermentation characteristics, microbial growth, enzyme activity and digestibility in the rumen. The administration of NIS solution to the rumen increased the digestion rates, the concentrations of Volatile Fatty Acid (VFA), growth rate and increased among of rumen microorganisms. However, had not much effect on ruminal pH value and ruminal NH3-N concentration. These results indicated that the addition of NIS could greatly stimulate the release of enzymes without decreasing cell growth rate in contrast to trends reported with aerobic microorganism. The results showed that NIS might be of use as an alternative feed additive to stimulate multiple enzyme activity and microbial growth in the rumen.