In tea rolling, the rolled twig rate is expressed as the regularity of twice curve equation with the extension of rolling time, the mathematical equation is: y=5.6277x–0.077x²–17.1439 and the broken cell rate is expressed as the regularity of the natural logarithm curve equation, the mathematical equation is: y=85.3e^-11.9/x . For improving the quality of tea, the rolling time would be controlled between 30~40βminutes.