According to legend, Mulian's mother was imprisoned in ancient times, and Mulian went to deliver meals every day, but every time she was robbed of food by prison guards and hungry ghosts, Mulian's mother became increasingly haggard. Mulian is a dutiful son, crying for this. When she met a fairy, she picked grass heads and mashed them to make juice, soaked the rice and dyed it black, and cooked a pot of black rice. The smell was fragrant and Mulian tasted delicious.

So black rice was sent to the prison every day, and the jailer was afraid of poison, so no one grabbed food. Mulian's mother actually felt better every day after eating black rice, and her body was strong, and she successfully passed the prison. Later, in order to commemorate the eldest son Mulian, people set the eighth day of April every year as the day to eat black rice.

On the eighth day of the fourth lunar month, Buyi people call it "Niuwang Festival", also known as "Opening Seedling Gate". After the first day of April, it began to farm and plant seedlings. I ate black rice on the day when I opened the seedling door. During this period of ploughing and planting seedlings, I was physically strong and healthy, so every household should eat delicious black rice.

Black rice is a kind of purple-black glutinous rice, which is made by collecting the leaves of wild plant Vaccinium bracteatum, boiling the glutinous rice in the boiled soup for a long time, then taking it out and steaming it in a wooden steamer. Black rice is oily and fragrant, and it is cooked by soaking glutinous rice in black leaves for a few hours. Eating black rice can dispel wind and detoxify, prevent mosquitoes from biting insects,