The paper is aimed to study the difference in yield and quality at different harvest time and determine the optimum harvest of planting Gentiana in Ludian traditional harvest period. The authors analyzed the variation in fresh weight, dry weight, dry discount rate, length, diameter, volume and the content of gentiopicroside, loganin acid, alcohol-soluble extract and total ash and made a comprehensive appraisal of yield, appearance quality and intrinsic quality by gray relational distance ideal Comprehensive Evaluation method. The results showed that there is a big difference in yield and quality both 2-year-old and 3-year-old Gentiana harvested in traditional harvest period and the comprehensive evaluation more better when harvested more later. It can be seen, Gentiana harvested the later had a better yield and quality in Ludian traditional harvest period. The harvest of Gentiana can be appropriate delayed depending on the particular circumstances of production.