21 species of Epimedium collected from China were used as study materials and common garden cultivated in Jishou university. We observed 16 floral quantitative traits including length of peduncle, diameter of flower, length and width of inner sepal, length of spur, pistil, stamen, anther and style, ovule number, diameter of pollen, pollen number and 6 floral quality traits such as inflorescence and spur type, color of petal, inner sepal and pollen of these species. The taxonomic significance was discussed through these floral traits. The results showed that: (1) The inner sepals of 21 species of Epimedium were petaloid and 4 petals specialized spur (except for Epimedium ecalcaratum). There were significant differences in floral traits among species, especially reflected in diameter of flower, length and width of inner sepal, length of spur, length of pistil, ovule number, pollen number, diameter of pollen. (2) The results of principal component analysis showed that the information load of traits including diameter of flower, length of inner sepal, length of anther, ovule number and diameter of pollen were larger, which played a major role in the classification of this genus. (3) The cluster analysis indicated that the 21 species could be divided into 4 clades: The flowers of Clade 1 were small, which petals were shorter than the inner sepals, and spurs were saccular or pocket. The flowers of Clade 2 were large, its petals were much longer than the inner sepals, and spurs were long. The flowers of Clade 3 were small, and the petals were devoid of spurs. The flowers of Clade 4 were small, the filament was obviously elongated, up to 10 mm, and the spur was subulate. (4) Compiled a key for 21 species of Epimedium based on the floral traits. This study found that the floral traits of Epimedium species based on the common garden cultivation have taxonomic significance and can provide some basis for the classification of the genus.