Recently there has been interested in the use of natural dyes in textile applications. Generally natural dyes can exhibit better biodegradability and have a higher compatibility with the environment. In this study, cotton, wool and silk fabrics were dyed with alkali extract of Arecae semen using various mordants, and their dyeabilities were discussed. Additionally the fastness to washing, perspiration, light, rubbing, and drycleaning and UV-B protection rate were also investigated. Cotton, silk and wool fabrics dyed with alkali extract of Arecae semen were colored in reddish yellow tint. The optimum dyeing condition of the colorants extracted from the Alecae semen was three repeated dyeing at $95^{circ}C$ for 1.5 hrs. The dyed fabrics by using mordanting methods improved the fastness to washing, perspiration and drycleaning, but the fastness to light and rubbing were not increased. The UV-B protection rate of the wool fabrics were increased by dyeing with extract of Arecae semen.