There is a famous fairy tale about this festival.
In the ancient past, there was a hero named HouYi who was excellent at archery. His wife was Chang'e. One year , the ten suns rose in the sky together and causing great disaster to people. Yi shot down nine of the suns and left only one to provide light . An immortal admire Yi and sent him the elixir . Yi did not want to leave chang'e and be immortal without her , so he let chang'e keep the elixir. But PengMeng , one of his apprentices , knew this secret. So , on the fifteenth of August in the lunar calendar , when Yi went hunting, PengMeng broke into Yi's house and forced Chang'e to give the elixir to him . Chang'e refused to do so . Instead , she swallowed it and flew into the sky. Since she loved her husband very much and hope to live nearby, she chose the moon for her residence. When Yi came back and knew what had happened, he felt so sad and he displayed the fruits and cakes Chang'e liked in the yard to commemorate his wife. People soon learned about these and they participate the activities with Yi.