Dyeing properties of sargent cherry of Prunus sargentii Rehder were investigated with silk fabrics. The absorbed wave lengths at UV-VIS spectrometer were 362nm, 386nm, 430nm, and 512nm. The K/S value showed high in following conditions: 100%(w/w) stock solution, 60 minutes of dyeing time, 80$^{circ}C$ of dyeing temperature, and 5 times of dyeing repetition. The K/S value showed higher in post-mordant than in pre-mordant, and the change of color did not appear in pre-mordant samples. They were colored greenish yellow in post-mordanted Cu and Fe. The highest dyeability and $Delta$E showed in post-mordanted Fe. The light fastness showed 3-4 in post-mordanted Fe, 1-2 in pre-mordanted Al, and washing and perspiration fastnesses showed also good results in post-mordanted Fe.