The purpose of this study was to identify the best dyeing conditions using onion's outer shell. and to apply to the method in practical daily life. To do this. we extracted quercetin from onion's outer shell and dyed several natural fabrics such as cotton, slack mercerized cotton, ramie. and silk. under the different conditions. Dyed fabrics were Investigated in the aspect of dyeability and colorfastness. The effective conditions for the light-fastness and washing-fastness also have been studied. The results of the experiment were varied with such conditions as temperature. time. pH degree. and treatment and types of mordants. The results are as follows ; 1. Fabrics dyed with onion's outer shell showed excellent dyeability even though there were no mordants, and the silk fabric dyed better than both cotton and ramie fabric. Furthermore, in the cases of repeated dyeing and treatment of mordants using AIK(SO$_4$)$_2$.12$H_2O$ and CuSO$_4$,.5$H_2O$ dyeability of specimen had been improved 2. Cellulose fabrics such as cotton, mercerized cotton and ramie showed the best dyeability under relatively low temperature in the range of 20~4$0^{\circ}C$. On the contrary to cellulose fabric, silk fabric showed the best dyeability under higher dyeing temperature. All fabrics had the higest K/S value at pH 3 regardless of the kind of fiber 3. Dyeing colors varied with the kind of mordants. Colors were turned into yellow in AIK(SO$_4$)$_2$.12$H_2O$ into Yellow-red in CuSO$_4$,.5$H_2O$ , and into green-Yellow in FeSO$_4$.7$H_2O$. As mordants, AIK(SO$_4$)$_2$.12$H_2O$, CuSO$_4$,. 5$H_2O$. FeSO$_4$.7$H_2O$. gallic acid and tartaric acid were used and especially AIK(SO$_4$)$_2$.12$H_2O$ showed the best dyeability and colorfastness in repeated dyeing. Mordants such as AIK(SO$_4$)$_2$.12$H_2O$ made fabrics have better chroma and washing-fastness though the light-fastness was poorer than non mordanting. 4. Repeated dyeing brought us deep color. When fresh dyebath was used each time, the dyeability was increased as the experiment was repeated more. When dyed with used dyebath several times, improved dyeability could not be expected. The optimal using times of the used dyebath was twice.