On a day more than 2,000 years B.C., when Shun became the son of Heaven, he led his men and worshipped heaven and earth. Since then, people have taken this day as the first day of the year, which is said to be the origin of the Lunar New Year, later called the Spring Festival.

Expanded:

The Spring Festival is the most important event in Chinese folklore. p>The Spring Festival is the grandest and liveliest festival in Chinese folklore, evolving from the yearly prayers and rituals of the ancient times. The Spring Festival is centered around the rituals of praying for the New Year, and is carried out in the form of activities such as getting rid of the old and bringing in the new, welcoming good fortune, worshipping the gods and ancestors, and praying for a good harvest, etc. It has a rich and colorful festive atmosphere, and is a cohesive blend of the traditional and cultural essences of the Chinese civilization.

China has a long history of celebrating the New Year, and some relatively fixed customs have been formed in the development of inheritance, many of which are still passed down to the present day, such as doing the New Year's goods, sweeping the dust, sticking the New Year's red, New Year's dinner, observing the New Year's Eve, paying New Year's money, worshipping the New Year's Eve, paying homage to the New Year, dancing dragons and lions, worshipping the gods and ancestors, burning firecrackers, burning fireworks, guanchuanchunsheng, New Year's routines, praying for blessings, going to the temple fairs, going up to the lanterns, and enjoying the lanterns. Traditional festival ceremonies and related customary activities are important elements of festivals, carrying colorful festival cultural connotations.

Reference: Baidu Encyclopedia - Spring Festival Customs