The changes of chemical components of Pu’er tea produced by solid state fermentation (SSF) of sundried green tea using Aspergillus niger were studied in this paper. The results showed that the main chemical components of sundried green tea such as polyphenols, catechins, thearubigins, flavonoid, theabromine, polysaccharide and oligosaccharide were converted obviously during SSF process of sundried green tea. When the sundried green tea was fermented for 40 days, the content of polyphenols, catechins, flavonoid , thearubigins, soluble oligosaccharide and tea extracts of the fourth pile sample were reduced 60%, 80%, 55%, 90%, 65% and 25%, respectively, but the content of theabromine and soluble polysaccharide increased by 4.5 times and by 5.7 times, respectively. It was suggested that the polyphenols, catechins, thearubigins, theabromine, oligosaccharide and polysaccharide of Pu’er tea could be used as characteristic components to determine the quality of Pu’er tea. The results also demonstrated that the esculent Pu’er tea was produced within short time by SSF of sundried green tea, and the product had the same content of characteristic components as the Pu’er tea stored for long time. Furthermore, the results revealed that the sundried green tea could not be transformed the characteristic quality of Pu’er tea without the process of microorganism.