Abstract: The effects of rolling time, water content of tea, piling temperature and piling duration on the quality of Luyuan yellow tea were studied in orthogonal design. Results showed that the effects of water content, piling temperature and duration on the contents of tea polyphenols and chlorophyll respectively were significant, but the effects of piling temperature and duration on the contents of protein, amino acids and soluble sugar were not significant. The effects of the mutual -factor interactions among waterc ontent,p ilingt emperature andd urationo n thec ontento fc hlorophyllw eres ignificant.W ith thei ncreasingo fw ater content, piling temperature and duration, the contents of tea polyphenols and chlorophyll appeared in a decreased trend. Lab color system was applied to describe the color of drying tea and tea liquor. The a values of drying tea and tea liquor were all negative and declined with the increasing of water content, piling temperature and duration, and the b value of drying tea and liquor were positive, the b value of tea infusion tended to increase, but that of drying tea showed no obvious trend. Combining with the organoleptic testing results and the changing trend of biochemistry components and color, the optimizing piling conditions were:water content of tea 40%, piling temperature 35℃, and piling duration 7h.

Key words:  yellow tea, Luyuan tea, piling