Abstract: Double flowers of Rhododendron moupinense were found in Sanjiang Township, Wenchuan County, Sichuan Province. Compared with the non-double flowers of Rhododendron moupinense in the same habitat, there were some different characteristics: the appearance of the flower was similar to that of camellia, the stamens were numerous and without a fixed number, the lower parts of the filaments changed into petaloid structures and with white pubescent, the pistils were degenerated. According to the analysis of the formation mechanism of double flowers, it is speculated that the reasons for the formation of double flowers of Rhododendron moupinense could be the mutation or abnormal expression of genes related to the development of flower organs, among which the C class of MAD-box genes and B class of MAD-box genes may play the major role.