In former times, door gods of China were divinities Taoists and common people believed to guard doors, as well as portraits of door gods for posting on doors. Door gods are widely popular among the Chinese people. Chinese New Year is the time for posting door god portraits. In the past, people believed that posting an image of a door god on the door could keep evil spirits away and bring back peace and luck. Door gods were even included into gods worshipped by Taoists, who would perform sacrificial rituals in honor of them.
The belief in door gods has been around for quite a long time. According to the pre-Qin Dynasty book the Classic of the Mountains and Seas, Shen Tu, Yu Lei, Reed Ropes and Peach Wood were ghost-driving gods.
In the Tang Dynasty, another door god named Zhong Kui, an excellent ghost catcher, became popular.