This study examines the character of "Tencel" named as Ecology Fiber and investigates the fitness of it as the textile and the satisfaction in dress when its fastness is compared with that of Rayon classified into Celulose textile. Dye experiment selected 100% Tencel, Rayon for the samples, which were dyed into the direct dye and Turky Blue and Blue of the rective dye and were washed twelve times by the automatic washer. After that, the dye experiment examines the light, laundering, perspiration, rubbing and the composite fastness of the perspiration and hight in the lists of the dye fastness. The results are as follows: 1. The experiment of the color fastness, especially in T-blue of the direct dyestuff, requiring the twelve times-repeatedly-washing by the detergent says that the color fastness of Tencel is superior to that of the cellulose textile ; Rayon. 2. The experiment of the light fastness says that the fastness of Tencel is superior to that of Rayon. 3. The experiment of the laundering fastness says that all of Tencel, Rayon shows the excellent result in the direct dye than in the reactive dye. 4. The experiment of the rubbing fastness says that although Tencel, Rayon show the remarkable result in the desiccant experiment than in the humid one, the rubbing fastness of Tencel is superior to that of others. 5. The experiment of perspiration fastness says that Tencel, Rayon have the closely tightened tendency not to be altered through the acid and alkali perspirations. 6. The experiment of the composite fastness of perspiration and light indicates that the artifical perspirations, though the light lets the fastness of textiles weeken, do very slightly make them loosen, which does not offer the outstanding result. This whole result show that the fastness of Tencel is superior to that of Rayon. The Korean Fiber Enterprise in clothing should make the new and ecological fiber "Tencel" by means of the large amount of investment, and the technique of handing and controlling about it, considering that the dangerous needle of environmental pollution has been slackening the close-related ecological knots of the global environment. global environment.