This study intends to analyze T-shirt designs, particularly in connection with pop art. 444 pieces of T-shirts which conveyed the pop art spirits of well-known designers were selected for five years from 2001 to 2005, through fashion magazines(Collection: Dong-ah TV, Collezioni: Italy). The findings are as follows. As for formative characteristics of pop art in T-shirts, previous studies were analyzed to set classifications criteria such as popularization of images, eroticism, lettering and graffiti, assemblage. The design factor of the image popularization includes everyday images, cartoon, celebrities, and caricature. Everyday images ranked first followed by cartoon, caricature and celebrities. The design factor of eroticism ranges from the see-through look, partial exposure of human body, symbolization of underwear, and to printing of sexy images. The see-through look was ranked first, followed by partial exposure of human body, symbolization of underwear, and printing of sexy images. The design factor of lettering and graffiti encompasses letters, numbers, symbols and logos. Adoption of letters, numbers or symbols was ranked first, followed by brand logos and graffiti. The design factor of Assemblage is closely related to a three-dimensional effect. Varied expressions are possible: combination of two different textiles and fusion of textile and non-textile. Combination of two different textiles are higher than fusion of textile and non-textile.