Both big black beans and small black beans belong to black beans. Although both are beans and both are called black beans, their effects are different, but eating more of them is beneficial to people's health. Small black beans have diuretic effect, and people with urinary system problems can eat more. And big black beans can tonify the kidney, and people with weak waist and knees and easy fatigue can eat more big black beans. So the functions of the two are different. The effect of small black beans is less than that of big black beans, so it is recommended to buy big black beans to eat. There are two types of black beans, one is called Wupi Qingren bean, the other is Wupi Huangren bean, and the other is Wupi Bairen bean. The nutritional value of Wupi Qingren bean is relatively high, and the content of protein is also higher than that of Wupi Huangren bean, while Wupi Huangren bean is mainly used to make candied fruit. These three kinds of black beans are very good for your health if you eat them often. You can eat more with your eyes, so you can eat black beans.