This study examines the costumes of clay figures decorated on earthenware of Silla from the mid 5th century to the 6th century. Costumes expressed in clay figures were examined based on actual observations and excavation reports, and identified through comparative analysis with other clothing materials. Hats were classified into Jeolpung-type hat, Jowoo-gwan, Gun, and Lip. There were two types of jeolpung-type hat, one with a semicircular side with a round top and one with a trapezoidal side with a straight top. In jowoo-gwan, there was one with natural bird feathers decorated on both sides of the jeolpung-type hat. Gun was divided into two types. As for the headband-type gun, it was clearly confirmed that the male wore that gun, but it was not clear whether the female also wore that gun. The headscarf-type gun showed various shapes, such as a shape with the front rising upward and the side rising straight, the tip bent forward, or the tip bent backward. In addition to this, a low-height and round headscarf-type gun was also confirmed. Such morphological diversity is recognized as a characteristic of Silla’s gun. Lip was a new type of hat that has not been mentioned in previous studies. There was a lip with a narrow brim on jeolpung-type hat. Also there was a clay figure with a wide brim around the head. The possibility was raised that the hat and the brim were worn separately without connecting them, based on the expression method of clay figures and the archaeological relics. Although the clothing was expressed relatively briefly, it was confirmed that both the jeogori as the top and the pants and skirt as the bottom were worn. In addition to the normal hip length jeogori, the long-length jeogori was worn in the clay figures from Wolseong. It is the earliest visual material showing long-length jeogori in Silla before unification. The research on clothing of clay figures reveals a part of Silla costumes from the mid 5th century to the 6th century, where there is almost no visual data related to costumes.