Abstract: Abstract: Peanut is viewed as one of the most important oil crops and food protein resources in China. Its production and planting area have been ranked the first and second in the world, respectively. The post-harvest drying of peanut is an indispensable process in its produce system. It is an important task to determine when to harvest and how to dry peanuts in practice, which will affect the final quality of peanut products. In order to investigate the effects of different harvesting dates and post-ripening drying methods on the quality of peanut, 3 drying modes including sun-drying of pods on plants, sun-drying of picked pods and air-drying of picked pods were adopted for Taihua-5 peanuts which were harvested on the original harvesting date, 1 week earlier and 2 weeks earlier, respectively, and the peanut qualities were analyzed. The results showed that hundred-pod weight and hundred-kernel weight of dried peanuts with the method of sun-drying of picked pods on plants were both higher than the other 2 methods, and the weight-increasing effect was more obvious for earlier harvesting date (P<0.05). As far as the same post-ripening drying method was concerned, hundred-pod weight and hundred-kernel weight of dried peanuts harvested 2 weeks earlier were significantly lower than the one week earlier and the original harvesting date (P<0.05). During the sun-drying period, the water content of peanut shells and kernels with the method of sun-drying of pods on plants were significantly higher than that with the method of sun-drying of picked pods. The difference in water content between the 2 methods was increased in the early stage of drying, and then gradually decreased until almost the same final moisture content was reached (P<0.05). No significant difference was observed for both crude protein content and crude fat content of dried kernels between the 2 methods of sun-drying of picked pods and air-drying of picked pods (P>0.05). However, the 2 indicators under the method of sun-drying of pods on plants were increased by 3% and 2%, respectively. The earlier the harvest date, the lower the crude protein and crude fat content. There was no significant difference in the total relative content of unsaturated fatty acids in the fresh-harvested kernels, dried kernels with sun-drying of pods on plants and dried kernels with sun-drying of picked pods (P>0.05), however, that indicator with the method of air-drying of picked pods was significantly higher than the fresh-harvested kernels (P<0.05). The contents of 8 major amino acids and the total amino acids content in peanut kernels with 3 post-ripening drying methods were ranked in descending order as sun-drying of pods on plants, sun-drying of picked pods and air-drying of picked pods (P<0.05). Electron microscopy photos of cross section of peanut pedicel with the method of sun-drying of pods on plants indicated that the peanut pedicel remained the channel space for the transportation and storage of water and nutrients in the early stage of drying, which provided the necessary conditions for the metabolism and accumulation of peanut pods. The results of the study can provide reference for peanut production practice.