This study aimed to suggest more appropriate and accurate festival costumes based on a comparative analysis on various reproduced costumes and a period review of traditional festival costumes. In particular, the comparative analysis examined festival costumes which appeared in Korean and Japanese festival parades during the Baekje Period. The Baekje Cultural and Sacheonwangsawasso Festivals were examined. A literature review as well as field research and digital restorative techniques were used in the study. The reproduction patterns of Baekje costumes from both festivals were compared with original Baekje costumes, demonstrating several differences in the configuration, material, color, and shape of the costumes in addition to the way they were worn. Based on the comparative analysis, Baekje costumes used in Festivals were grouped into three categories: King`s Costume, Queen`s Costume, and Government Official`s Costume. Dress sketches and 3D illustrations also have been presented.