At the beginning of the 20th century, Cartier developed Art Deco jewelry designs that have been used as design inspirations to this day. The purpose of this study is to analyze the characteristics of the Art Deco jewelry designs of Cartier in the early 20th century. Regarding the research method, this study explored the jewelry designs from 1904 to 1939 by extracting 288 analysis subjects from Cartier’s exhibitions, auction picture books, and foreign books, and analyzed the characteristics in terms of design motifs, colors and materials. The results of the study are as follows. Regarding the design motifs, 73% were geometric motifs, and 66% were a combination of circular shapes and polygons, the most frequent. In terms of colors, 69% were chromatic in color, and vivid colors were mostly used in the order of red (24%), - green (19%), and - blue (14%). Of the materials, 92% of the metals consisted of platinum, and gemstones were used in the order of diamonds (41%), - onyx (13%), - emeralds (11%), - rubies (9%), and - sapphires (8%). In the early 20th century, Cartier’s Art Deco jewelry designs featured abstract and geometric motifs, vivid colors and strong contrasts, platinum and precious gemstones. This study is meaningful in that it explores the competitiveness of Cartier’s designs and provides practical ideas to combine Art Deco style with contemporary jewelry designs successfully.