Dancing along with mankind has existed in various ways form old age to the present. This dancing combined with artistic meaning is called the art of dancing. This study is mainly about the functions decorations and expressions of dancing costume and the claracteristics of the costumes by the 20th century designers Leon bakst Oskar Schlemer Pablo Picasso. The dancing costume were not so much different from those of the public from old age to middle age. In 18th and 19th centuries the length of the cotstumes become short from the knee to the thigh. The functions have much to do with the development of dancing for example the appearance of toeshoes. The costumes are designed not to prevent the movements of dancers smooth line in old age and ladylike vend high-blown line in the 18th and 19th centuries. Cotton and hemp textiles are turning into the transparent forms such as lace and gauge. The personal ornaments earings and necklaces have change into the pattern with wings and tassels. The dancing costumes of Leon Bakst Oskar Schlemer and Pablo Picasso are designed after the due consideration of body shape. Bakst focused on the beauty of smooth lines with splendid colors and decorations. Schlemer analyzed the body abstractly and metaphysically and expressed it with detaile and simple lines. Picasso emphasized cubic forms with cubism and expressed the characteristics of costumes with clear colors and smooth curved line. Bakst Schlemer and Picasso made the early 20th century the age of functional dancing costumes putting a light on the concept of space and foundation for the modern dancing costumes.