Since 1956, the fossils of Kaiyuan Dryopithecid (dating back to 15 million years), Lufeng Ramapithecus (dating back to 8 million years), and Yuanmou Man (dating back to 1.7 million years) have been unearthed in Yunnan, testifying its significance as an area where the human race originated and an important pre-historic human habitat. The Paleolithic and Neolithic cultural relics discovered in Yuanmou County and the Dianchi and Er'hai lakeside areas show that Yunnan is also an important location of early human culture and provide evidence of the role it played in the long process of human evolution.

In about 286 BC, General Zhuang Jue of the Chu State in the mid reaches of the Yangtze River led his army into Yunnan. At that time, Yunnan was inhabited by such ancient tribes as the Dian, the Yelang, the Kunming and the Ailao, all of whom are the ancestors of many ethnic groups found in Yunnan today. Zhuang Jue subdued these tribes and unified the Dianchi area. The war, however, prevented Zhuang Jue and his men from returning to their homelands. As a result, they settled down in the Dianchi area eventually and gradually became assimilated to the local tribes. They brought to their new home the more-advanced culture of the Yangtze River valley.

In 221 BC, following the unification of China by the first Emperor of the Qin Dynasty, Li Bin, the governor of Shu (nowadays Sichuan Province), built a "five-chi(one-foot) wide passage" that began in Yibin of Sichuan Province and ended in Qujing of Yunnan Province. The Qin court also dispatched officials to Yunnan and other parts of Southwest China to execute direct administration over these regions, thus making Yunnan an integral part of the unified China. The policies of the Qin Dynasty to develop the border areas were carried on and further improved in the Han Dynasty. 

In the 7th century, a new era began with the ruling of the Tang Dynasty over Yunnan. In 707 A.D, the Tang troops defeated an invading Tubo army (in Tang and Song Dynasties, Tubo refers to the Tibetan area, same hereunder) in the Er'hai Lake area, and helped the local chieftains of Nanzhao  establish  unified rule over this area (at that time, there were six tribes in Er'hai Lake area; Nan means south, Zhao means tribe, Mengshe tribe was just in the utmost south of Er'hai lake, so also named Nanzhao, namely the south tribe); and the Nanzhao Kingdom was finally established by Pi Luoge, the grand chieftain then, who was bestowed as the King of Yunnan by the Tang Court. During the 247 years in which it ruled, the Nanzhao Kingdom remained a subordinate to the Tang Court and also had functioned as a southwestern outpost of the Tang Empire against Tubo.

In 937, the Nanzhao Kingdom was replaced by the Dali Kingdom. The rule of this new kingdom lasted for nearly 300 years, during which it remained also loyal to the central government and maintained the boundary lines defined since the Nanzhao period.

In 1253, Kublai Khan commanded the Mongol troops to conquer the Dali Kingdom. Then the Yuan Government set up the province of Yunnan as one of China's eleven provinces at that time; since then Yunnan has become a provincial administration, and the capital was shifted from Dali to Kunming; under the rule of Sayyid All Omer Shams al-Din, a member of the Hui minority, the economy of Yunnan Province developed rapidly; in addition, chieftain system was established in Yunnan then.

In 1381, the Ming Government commanded its troops to enter and control Yunnan, and multitudes of Chinese Han began to immigrate as the majority while other ethnic groups became the minorities. The Ming Government also abolished the appointment of the native officials and offered posts to the Hans; that is the well-known Power-Shift Practice. In the Ming Dynasty, foundry industry of Yunnan, especially mining and metallurgy prospered, with the outputs of silver and copper ranking first in whole China; and Mr. Zheng He, born in Yunnan, made his fame as China's great navigator in the 15th century.

In 1644, the Ming Dynasty was overthrown. Some members who were against the Qing and adherents of the Ming enthroned a prince (Emperor Yong Li), establishing the Southern Ming Dynasty. Once Emperor Yong Li settled in Yunnan, he immediately made Kunming the capital. Years later, one general of the Qing Dynasty, Wu Sangui, hanged Emperor Yong Li in Bisipo of Kunming and Yunnan was in his hands; in 1681 during the reign of the Kangxi Emperor, the Qing Government suppressed rebellions of the three vassal states, including Wu Sangui (King of Pingxi); when it was the Emperor Yongzheng Period,  the Government earnestly carried out the policy, "To appoint Chinese Han officials other than the local " in Yunnan, and also built Yidong, Yixi and Yinan (East Road, West Road and South Road, which together refer to Yun