Black rice is a kind of rice with both medicine and food, and its quality is good. Black rice has a long history of planting and is an ancient and precious rice variety in China. According to legend, it was first discovered by Zhang Qian, the prince of Bo, more than 2,000 years ago when he was Emperor Wu of Han Dynasty. Traditional Chinese medicine believes that black rice has significant medicinal value, and ancient agricultural medical books record that black rice has the effects of nourishing yin and tonifying kidney, strengthening the body and warming the stomach, improving eyesight and promoting blood circulation, clearing liver and moistening intestines, promoting diuresis and replenishing essence, nourishing lung and relaxing muscles and tendons. Can be used as medicine, and has particularly good curative effect on dizziness, anemia, gray hair, soreness of waist and knees, night blindness and tinnitus. Long-term consumption can prolong life. Therefore, people commonly call it "medicated rice" and "longevity rice". Because it is most suitable for pregnant women and parturients to replenish blood, it is also called "moon rice" and "blood rice". Emperors of past dynasties also regarded it as the treasure of palace health preservation and called it "Gong Mi". It is produced in many places in China, such as Shaanxi black rice, Guizhou black glutinous rice and Hunan black rice. There are two kinds of grain types: indica rice and japonica rice, and the grain quality is divided into waxy and non-waxy. Brown rice is black or dark brown. The main nutrients (brown rice), based on dry matter, contain crude protein 8.5- 12.5%, crude fat 2.7-3.8%, carbohydrate 75-84% and crude ash 1.7-2%. The contents of vitamins, trace elements and amino acids are higher than those of ordinary rice. High edible value, besides cooking porridge, it can also be used to make various nutritious foods and make wine. Modern medicine has proved that black rice has the effects of nourishing yin and tonifying kidney, strengthening spleen and warming liver, improving eyesight and promoting blood circulation. Most of the nutrients contained are concentrated in the black cortex, which is not suitable for finishing. It is best to eat brown rice or standard third-class rice. When cooking porridge, soak black rice in clear water for one night in summer and two nights in winter, with less elutriation times. Soaked water should be cooked with rice to preserve nutrients.