Jiaozi is regarded by many Chinese people as the best food. Making jiaozi during Spring Festival is customary, especially for the people in northern China. Originally called jiao er, jiaozi was allegedly invented by Zhang Zhongjing, China's medical sage.

In the late Eastern Han Dynasty, owing to disasters in many places, many people suffered from various diseases. There was a famous doctor named Zhang Ji, style name Zhongjing, in Nanyang. He studied medicine very diligently since childhood and later became a founder of traditional Chinese medicine. Zhang Zhongjing was skillful in medical treatment and could cure various difficult and complicated cases of illness. He also had lofty morals and earnestly treated every patient, poor or rich. As an official in Changsha, he cured many patients. One year during a plague, he distributed free medicine from a vessel in front of his government office. Changsha people respected him very much. After Zhang Zhongjing retired from his post, he came back home. Walking along the Baihe River in his hometown one day, he found many poor people suffering from cold and hunger, and they had ulcers in their ears. He felt sorry for them and decided to help. After Zhang Zhongjing returned home, many people came to him for medical treatment. He was very busy every day. But he still remembered the poor people with ulcers in their ears. He continued his practice in Changsha and asked his apprentices to build a shed as his clinic on the vacant lot in Dongguan in Nanyang. His clinic opened on Winter Solstice and his apprentices distributed medicine to the poor for free. His medicine was called "anti-chill jiao er soup." He boiled mutton, chili and other medicines to raise inner heat in the vessel. After the materials were boiled, Zhang Zhongjing took them out and minced them. Then, he used dough slices to wrap the stuffing and made into the shape of ears. After boiling the 'ears' in water, the jiao ers were distributed to the patients. Each patient could have two jiao ers and one bowl of soup. After eating the soup, the patents would be warm, their blood circulation would be smooth and their ears would be warmer. After a period of time of treatment, the ulcers in their ears healed. Zhang Zhongjing's donations lasted until the eve of Spring Festival. During Spring Festival, people celebrated Chinese New Year, and celebrated the recovery of their ears. They also followed Zhang Zhongjing to make jiao ers and ate them during Spring Festival. People call the food jiao er, jiaozi or pianshi, and eat them on Winter Solstice and Spring Festival so as to commemorate the dates of Zhang Zhongjing's contributions and medical treatments.

Nearly 1,800 years have passed since Zhang Zhongjing's contributions. But his story of donating "anti-chill jiao er soup" has been handed down among the people. In Winter Solstice and Spring Festival every year, people eat jiaozi and remember Zhang Zhongjing's kindness. Today, we do not need to cure ear ulcers, but jiaozi has nonetheless become the most common and most popular food.