[Objective] This study aimed to analyze the interaction between genotype of flavonoids of barley grain and environment, to increase the flavonoid content of barley grain in cultivation and breeding. [Method] In this study, the content of cate- chin, myricetin, quercetin and kaempferol of barley grain planted in Kunming, Qujing and Baoshan were determined by HPLC, and the genotype, environment, genotype- environment interaction of the flavonoid content of barley grain were analyzed. [Result] According to the experimental results, the genotype variance, environmental variance and G x E interaction variance of catechin and kaempferol contents show the same trend: genotype variation 〉 environmental variation 〉 G × E interaction variation, which all reach a extremely significant level; the genotype variance, envi- ronmental variance and G × E interaction variance of quercetin and total flavonoid contents show the same trend: genetype variation 〉 G × E interaction variation 〉 environmental variation, which all reach a extremely significant level; the genotype variance and environmental variance of myricetin content both reach a extremely sig- nificant level, while the G × E interaction variance reaches a significant level, showing an order of genotype variation 〉 environmental variation 〉 G × E interaction variation; the genotype variance, environmental variance and G x E interaction vari- ance of total flavonoid content show an order of genotype variation 〉 environmental variation 〉 G × E interaction variation. Among different barley varieties, Ziguang- mangluoerling and Kuanyingdamai in Qujing, Kunming and Baoshan have relatively high content of quercetin, while other barley varieties barely contain any quercetin. The grains of Ziguangmangluoerling and Kuanyingdamai are purple, while the grains of other barley varieties are yellow. [Conclusion] Four main flavonoids and the total flavonoids of barley grain are mainly under genetic control and affected by genetic- environment interactions; the purple barley grains contain high content of quercetin.