0523 GMT September 18, 2019
In China, hundreds of millions of people are travelling home in what is considered the world's biggest annual human migration, BBC reported.
State media said about three billion passenger trips will be made by plane, train and car over the 40-day period.
It is a public holiday in many places with ethnic Chinese populations such as Taiwan, Singapore and Malaysia.
The festival is known as Tet in Vietnam and Seollal in South Korea, and is traditionally a time to be with family.
In a speech at the Great Hall of the People on Tuesday, Chinese President Xi Jinping extended Lunar New Year greetings to Chinese people everywhere.
This year, the government is urging people not to set off firecrackers, amid rocketing pollution levels in cities.
Also known as the Spring Festival in China, celebrations kicked off with a large meal, known as the reunion dinner, on New Year's Eve on Wednesday.
Families make great efforts to be together for this, with some people travelling for days.
Celebrations in Shanghai, and in many other Chinese cities, have been toned down this year after a stampede at a New Year event in January left 36 people dead.
On Wednesday, Hong Kong Leader CY Leung also gave his holiday message, describing the last year as full of conflicts and urging citizens to "be like sheep".
Late last year, a pro-democracy movement brought crowds onto the streets, blockading parts of the city and deeply dividing public opinion.
"Sheep are widely seen to be mild and gentle animals living peacefully in groups," Leung said.