【Objective】In order to provide a theoretical reference and guidance for variety breeding and cultivation of improved yam varieties and develop the yam industry, the traits of quality and yield were evaluated synthetically with 31 yam germplasm resources as materials. 【Method】The tuber yield, character and contents of soluble protein, starch, sucrose, reducing sugar of 31 kinds of yam germplasm resources were analyzed and evaluated by Membership Function. 【Result】The yield and quality were different in different germplasm resources. All germplasm resources could be divided into 3 types including long, medium and short according to tuber length, but they could be divided into 7 types according to yield. The first type had the highest yield which was greater than 55 000 kg/hm2, such as HZ-2 and G15, the seventh type had the lowest yield which was less than 15 000 kg/hm2, such as Hubeida, Tiegun, Hubeixiao, and SY2. Comprehensive analysis with Membership Function indicated that seven germplasm resources with long or medium tuber length had better nutritional quality and higher production, which were GH5, G1, GH-9, G15, HZ-2, BL-5 and BL-2, respectively. There were seven germplasm resources with short tuber length had better nutritional quality and higher production, which were PZ-1, Wild species, Tujia white, PZ-3, BL-3, Yuebei NO. 2, and Zhejiang red, respectively.【Conclusion】Optimum germplasm resources with long or medium tuber length such as GH5, G1, GH-9, G15, HZ-2, were suitable for breeding materials of top quality and high production or fresh food varieties, while optimum germplasm resources with short tuber length such as the Wild species, Tujia white, Zhejiang red, were more suitable for mechanized planting and processing. [ABSTRACT FROM AUTHOR] more...