There are three different answers to Lake Baikal: the explanation in the World Cultural and Natural Heritage Scenery Photo Map Edition is "a rich lake"; the World Cultural and Natural Heritage Colored Edition records that the local Buryats call it "Baikal-Darai", which means "a natural sea"; and the text in the World Wonders Exploration Records is: "The name Baikal is said to have been given by the Kurikans who lived here about 1,300 years ago, meaning "a lot of water". The word Lake Baikal comes from the ancient Sushen language (Manchu) "Beihaier Lake", which was called "North Sea" during the Han Dynasty in China. The English word "baykal" is a transliteration of Chinese. The Russian word "baukaji" originated from Mongolian, which is a transformation of "saii" (rich) plus "kyji" (lake), meaning "a rich lake", and is named after the abundance of many kinds of fish in the lake. According to the legend of the Buryats, Lake Baikal is called "Baikal-Darai", which means "a natural sea". Lake Baikal first appeared in written records 110 years ago. An official of the Han Dynasty in China called Lake Baikal "North Sea" in his notes, which may be the origin of the Russian name of Lake Baikal. There is another simple explanation for the origin of the name of Lake Baikal: the Turks called Lake Baikal "Rich Lake", and the Turkic "Rich Lake" gradually evolved into the Russian "Lake Baikal". In my country, it was called "Baihai" in the Han Dynasty, "Chrysanthemum Sea" in the Yuan Dynasty, "Baihaier Lake" in the "Records of Foreign Lands" in the early 18th century, and "Baihaer Lake" in the "Records of the Great Qing Dynasty". The Mongols called it "Dalai Nor", which means "sea-like lake", and the early Russian colonists also called it "Holy Sea".

The earliest residents living by the lake were the ancestors of the Sushen tribe 7,000 years ago. Later generations learned about their lifestyle from the murals and other objects they left behind. During the Western Han Dynasty, "Lake Baikal" was under the control of the Xiongnu and was called "North Sea". Su Wu was exiled to the "North Sea" by the Xiongnu king Shanyu to herd sheep. Su Wu survived 19 years by the North Sea and finally returned to Chang'an, the capital of the Han Dynasty. During the Eastern Han Dynasty, the Three Kingdoms, and the Western Jin Dynasty, "Lake Baikal" was under the control of the Xianbei; during the Sixteen Kingdoms period of the Eastern Jin Dynasty, "Lake Baikal" was renamed "Yusini Water"; during the Southern and Northern Dynasties, "Lake Baikal" was first controlled by the Rouran and then by the Turks, and the name was still "Yusini Water"; during the Sui Dynasty, "Lake Baikal" was controlled by the Eastern Turks and renamed "North Sea"; in the early Tang Dynasty, "Lake Baikal" became part of the territory of the Tang Empire, and "Lake Baikal" was also renamed "Small Sea"; after the Eastern Turks (historically known as the Later Turks) restored their country, "Lake Baikal" returned to the Turks, and then to the jurisdiction of the Uighurs, and was still called "Small Sea"; in the Song Dynasty, "Lake Baikal" was controlled by the Mongolian Bala (pronounced là) Hu tribe; in the 13th century, the Buryats, descendants of the Mongols, also came to the Lake Baikal area. Neither the Turks nor the Buryats were able to change the lifestyle of the Evenki people. During the Yuan Dynasty, "Lake Baikal" was included in the territory of the Mongol Empire and belonged to the "Lingbei Province"; during the Ming Dynasty, "Lake Baikal" was controlled by the Oirat tribe; in the Qing Dynasty, Khalkha Mongolia and Junggar Mongolia were successively controlled or conquered by the Qing army. However, in the Treaty of Nerchinsk between China and Russia, the area east of Lake Baikal belonging to Buryat Mongolia was assigned to the Russian Empire by Emperor Kangxi. During the reign of Emperor Yongzheng of the Qing Dynasty, the Treaty of Burlinsky and the Treaty of Kyakhta, which divided the middle section of the Qing-Russian border, were signed, marking the final complete isolation of the Central Plains dynasty from Lake Baikal. In 1643, when Yenisei Cossack Kurbat Ivanov came to the Lake Baikal area, the Buryats were already the "masters" of the Lake Baikal area. In 1729, Peter the Great sent Germans to explore Siberia, and he conducted the first scientific survey of Lake Baikal. In the early 20th century, scholars drew the first full map of Lake Baikal and measured the depth of the lake. In 1977, Soviet scholars used a deep-water survey instrument to survey Lake Baikal. Many secrets of the lake were "exposed" under the searchlight of the survey instrument, and some previously suspected things also "walked" out of the dark lake, which caused a sensation at the time. So far, no instrument can detect the bottom of Lake Baikal, and the deepest point of the lake is not 1,637 meters, and it is still impossible to detect.