It is said that Chong Er, one of the powerful chief princes in the Spring and Autumn Period, was forced to leave his homeland when he was young.

Once, he was left in a desolate area where he could not find anything to eat. Tired and hungry, he couldn’t even stand up himself. His ministers were worried and they didn’t know what to do. Chong Er must eat something or he could die. At this time, Jie Zitui, one of the ministers, went to a place where no one could see him and cut some meat from his own leg. He boiled some soup with this meat and sent it to Chong Er. Chong Er was moved to tears when he learned the truth.

19 years later, Chong Er became an emperor and he rewarded many ministers who had helped him during that hard time. However, Jie Zitui was missed. Many people were angry for they felt sorry for Jie Zitui. But Jie did not want to ask for awards, so he left to Mian Moutation with his mother.

The emperor was regretful when he heard that and decided to do something to make it up. He went to see Jie Zitui personally, but only found that Jie was not at home. Someone told him that Jie was hiding in Mian Mountain and suggested to the emperor to set on fire the mountain to forced Jie to come out. But they didn’t see Jie until the fire died out. Jie and his mother died under a big willow tree. The emperor cried and ordered that this day to be “Cold Food Festival” and that no one can use fire on that day.

A year later, when the emperor held sacrificial activities for Jie Zitui at Mian Mountain, he was amazed that the willow tree was back to life again. So he gave the tree a name “Qingming Willow”, and the day (the next day of Cold Food Festival) was called “Qingming” (Tomb-sweeping Day) after that.

Source: baike.baidu.com