The painted plate excavated at the Heavenly Horse Tomb was recently photographed with infrared light, providing information about its burial contexts, manufacture technology as well as function. This study also examines auspicious birds and horseback riding figures painted on the entire surface of the plate and as compared with related materials of the neighboring countries. The results of the analysis are as follows. The painted plate was buried in the coffin together with a number of different objects in a specific order. The plate seems to have been buried at the end with a saddle flap depicting the heavenly horse, saddle and stirrups. The manufacture of the painted plate is comprised of two phases: forming the shape and painting of the plate. The painted plate is assumed to have been attached to a crown or used as an ornament on the horseback, judging from its burial contexts and painted examples in Goguryeo wall paintings. Auspicious birds and horsemen painted on the plate can be seen on the painted lacquer and metal works excavated from Silla tombs dating to the 5th and 6th centuries. They are also found in the wooden and metal crafts of Baekje and Goguryeo wall paintings. Therefore, it can be assumed that the bird-horseman iconography was popular and widely used in Silla, Baekje and Goguryeo during the same period. Moreover, such iconography can be seen in numerous examples from Wei, Jin and Northern and Southern dynasties of China as evidenced in wall paintings and pictorial stones of tombs in the northeast, northwest, and south regions and Nanjing area. This fact clearly shows that East Asian countries, including Silla, were culturally tied to each other. However, further details are needed for an in-depth study of the analysis and comparison of iconography.