Abstract: Taken Yunnan sun-dried green tea as raw material,the quality difference of pu-erh tea fermenting by using the automatic fermentation tank(patent number:200920111698.9) and traditional method was analyzed. Through the chemical components and sensory evaluation,results showed that the quality of samples processing by two methods has no significant difference ( p = 0 . 9484 ) . Contents of flavone , caffeine , tea polyphenols,amino acid and theabromine of samples fermenting by automatic fermentation tank were higher than those of fermenting by traditional method. The aroma and taste of pu-erh tea was best formed fermentation 24 days by using automatic fermentation tank,while it needed 56 days by traditional method. It provided the experimental data for application of automatic fermentation tank.