The anthocyanin isolated from the petals of Erythronium japonicum was elucidated as delphinidin 3-rutinoside on the basis of PPC and UV spectral evidences. To evaluate phytochemical and botanical utilization of this plant, the quantitative analysis of anthocyanin content was carried out by using the visible absorption spectra at 540nm. By the results of our experiment, it was found that the anthocyanin content of petals collected from the summit of Mt. Odae are higher than that of the lowest region. However, there is no significant difference between the anthocyanin contents of the petals collected from the east- and west-side area of the mountain.