People across China are lighting incense sticks and praying at temples to wish for an auspicious start to the Lunar New Year.
Thousands of people have visited Beijing's major temples, as today is the first day of the Year of the Rooster.
Wearing heavy winter coats, they lit incense sticks and bowed as they prayed for good fortune and health.
As many as 80,000 people were expected at the Lama Temple in central Beijing, state television reported.
Beijing's sprawling spring festival temple fair opened at Ditan Park, where empty tree branches were festooned with red lanterns and traditional goods and foods on sale.
Other New Year traditions include eating dumplings in northern China and lighting fireworks.
Beijing's government called on Communist Party cadres and government staff not to set off firecrackers over environmental concerns.
Local media reported air pollution levels in Beijing and several other cities still shot up on Friday night and early Saturday morning.
Ethnic Chinese and others around the world are also marking the holiday with celebrations and visits to temples.
Large crowds gathered in Hong Kong and Malaysia on Friday night.
In Rio de Janeiro, crowds watched a dragon dance and a performance of tai chi in front of a picture of Rio's famous Christ the Redeemer statue.
New York brought in the holiday with fireworks on Thursday night over the Hudson River.
In Pyongyang, North Korea, a large crowd laid flowers in front of bronze statues of founding leader Kim Il Sung and his son, Kim Jong Il.