Purple-kernel walnut is one of the endemic breeds in southwest China. In order to select high-quality varieties, the fruit characteristics, main nutritional component and fatty acids composition of 11 kinds of purple-kernel walnuts were determined. The results showed that: WR03 met the requirements of first-grade walnut; 22 kinds of fatty acids, including acetic acid, propionic acid, butyric acid, octanoic acid, pelargonate, capric acid, laurel acid, myristic acid, pentadecanoate, 7,10-hexadecadienoate, (Z)-7-hexadecenoic acid, palmitoleate, palmitate, heptadecanoate, 8,11-octadecadienoate, linoleate, oleate, stearate, nonadecanoate, 11-eicosenoate, eicosanoate, behenate, were detected. Oleic acid, linoleic acid, palmitic acid, stearic acid were the main ingredients in purple-kernel walnut. The qualities of the purple-kernel walnuts selected this time were ordinary without high quality single plant.