In the current study, Phyllostachys edulis with uniform growth characteristics, which grew in consistent geographical environment, as the materials, we measured the difference of bamboo appearance quality (individual weight, maximum diameter, length, and edible rate), nutritional quality (starch, protein, fat, soluble sugar, and vitamin C), flavor substances (tannins and oxalic acid), cellulosic substances (cellulose and lignin), and different amino acids of winter bamboo shoots under irrigated and nonirrigated treatments. We aimed to explore the effect of irrigation on the shoot quality of P. edulis in winter, which provided the theoretical basis for the scientific cultivation of winter bamboo shoots. The results showed that: (1) the treatment of irrigation significantly increased the individual weight, maximum diameter, length, and edible rate of winter bamboo shoots (P<0.05). (2) The treatment of irrigation significantly increased the contents of starch, vitamin C, and reduced the contents of tannin, oxalic acid, cellulose, and lignin (P<0.05). The treatment of irrigation had no significant impact on the contents of protein, fat, and soluble sugar etc. (3) The treatment of irrigation significantly increased the contents and proportion of essential amino acids, semiessential amino acids, and umami amino acids (P<0.05). In contrast, it had no significant effect on the total contents of sweet and bitter amino acids. The treatment of irrigation had a significant effect on the shoot quality of winter bamboo. Irrigation can improve the appearance, flavor substances, cellulose substances, essential amino acids, semiessential amino acids, umami amino acids, and other indicators of winter bamboo shoots, to improve the shoot quality of winter bamboo.