The composition and concentrations of flavonoids in the leaves of 107 different cultivars or taxa of lotus(Nelumbo) were characterized and compared, and the effect of drying or fresh-freezing leaves on flavonoid composition and content was investigated. Results show that significantly higher flavonoid levels were present in fresh-frozen than in dried tissue, while preparation technique produced no effects on flavonoid composition. Quercetin derivatives including hyperoside, isoquercitrin, and quercetin 3-O-glucuronide were the dominant flavonoids in lotus leaves, accounting on average for 15.87%, 16.26%, and 50.20% of total flavonoids, respectively. Lotus taxa used in seed production had the highest flavonoid content (20–45% higher than other cultivars). Principal component analysis allowed the cultivars to be divided into three well-characterized groups based on their flavonoid content. The results of this study should be of value to the lotus- processing industry with regard to tea and food additive production.