The purpose of this study is to provide basic data of dress design by researching three-dimensional decorative techniques representing flowers, a popular motif in dress design. This study analyzed 44 dresses that were presented in Valentino collection. The result of this study is as follows: First, the detailing expression method can show various patterns and colors through embroidery technique, sub-materials, and bonding techniques in embroidery, beads flower, and ribbon flowers. Second, the fabric flower technique expressed flower image in three-dimension in more various images than do either the ribbon or beads flower technique. Fabric flowers are mostly made from the same material as dresses. The expression technique of fabric flower is classified into the following three classifications: 1) A technique underlying a flower image with one, two and three large flowers, 2) a technique decorating a large area with a number of an identical motif, and 3) a technique highlighting a part of the body or design line by attracting eyes to one point, creating a corsage decorated where a designer wants to emphasize. Third, a silhouette technique realizes a flower image with a silhouette of a dress like sculpted structure and it is thus used less than a detailing expression technique. A flower image is expressed by making use of body lines or emphasizing the face. Finally, flower images on a dress were realized as a full blossomed flower, through visually streamlined shapes and curved lines.