This study, at first we extracted natural dyes from seaweed(Sargassum thunbergii, Hizikia fusiforme, Sargassum horneri). Then. we dyed cotton, wool, and silk with the extracted dyes. This study purposes to find the best one for dyeing with seaweed in order to develop a more efficient method of dyeing with seaweed and investigates the colorfastness to washing, light, sun protection factor, antibiotic activities, deodorization after mordanting treatment. of seaweed. The mission of general agricultural education is to prepare and support individuals for careers, build awareness, and develop leadership for the food, fiber, and natural resource systems. In response to the changes of the recognition and attitude toward agriculture, agricultural education also should be developed and adapted to the circumstances. And The Researcher took an observation on color change, color fastness to washing and color fastness to light after mordanting treatment. And the following results have been obtained. 1) Dyed cotton, wool, and silk fabrics with the extract of seaweed are generally brown. 2) Wool. silk, and cotton, in this order, are of good dyeability; Wool fabrics have the highest dyeability and cotton fabrics have the lowest. 3) Colorfastness to washing, light, sun protection factor, antimicrobial activity acessment, deodorization are all high. 4) The seaweed-dyed fabrics were shown to have much higher sun protection factor than the non-dyed fabrics, and the seaweed-dyed fabrics with mortanting treatment showed the following result; ranged from anged from from 93.1% to grade 99.2%. 5) The seaweed-dyed fabrics were shown to have much higher antibiosis than the non-dyed fabrics, and the seaweed-dyed fabrics with mortanting treatment showed the following result; ranged from 91.3% to grade 99.9%. 6) The seaweed-dyed fabrics were shown to have much higher deodorization than the non-dyed fabrics, and the seaweed-dyed fabrics with mortanting treatment showed 99.9%.