Masks, known as dog heads in ancient times, are also called masks, masks and masks, which mainly come from primitive witchcraft rituals or primitive music and dance. During the Shang and Zhou Dynasties, the bronze manufacturing technology was highly developed, and sacrifices were popular in all walks of life. Nuo sacrifices flourished around the world, and the development of masks ushered in the first climax. During this period, the fangxiang mask with the longest inheritance time and the widest radiation area appeared in China. During the Qin and Han Dynasties, Nuo sacrifice and hundred operas were the most commonly used masks, followed by funeral and hunting. The Sui and Tang Dynasties was the second peak of mask development. During this period, wood, bamboo, cloth and silk replaced bronze, hides and other materials. Masks are widely used in music and dance. At this time, the mask of the warrior Lan Ling appeared. The aesthetic function of masks began to occupy the first place. The Song and Yuan Dynasties were the third peak of mask development in China, and court Nuo opera and folk Nuo opera prevailed. According to the shape, it can be divided into mask, false head, facial decoration, mask, portrait, mask, face change and other types. Masks are the most common, and people usually call them masks. Most masks are as big as people's faces, and they are worn on people's faces, leaving holes in their mouths and eyes for talking, singing and facing external objects. Another important feature is that most of them are plane reliefs, convex and concave, slightly curved, and a few are flat, made of painting, weaving and cutting. Masks are also widely used, such as dance, drama, war, exorcism, sacrifice and various folk activities. False head refers to a hooded mask, which mostly covers the whole head when worn, leaving the position of eyes and mouth to facilitate rap performance. False heads appeared earlier than other masks in history, and most masks in primitive society belonged to false heads. After the Song Dynasty, the important position of artificial head in mask was gradually replaced by artificial face. Face ornaments are small masks worn on the body as decoration and evil spirits. Ties are usually placed on the chest, arms or waist. Small holes are drilled at the top or both sides for threading. Shapes can be divided into two types: human face and animal face, and human face shapes are the majority. People often carve portraits of their deceased relatives on decorations and wear them on their chests to express their grief. Most surface decorations are made of plane relief, and some are made of intaglio line carving or other methods.