In an elaborate, nationally televised gala at a Beijing sports arena on Friday, senior Chinese leaders introduced the mascots - each one the colour of one of the Olympic rings.
The ceremony was time to coincide with the 1000-day countdown until the opening of the games.
"The five friendlies are an incredible little family carefully chosen by Beijing 2008 to represent all of China to carry a message of friendship to the children of the world," International Olympic Committee president Jacques Rogge said in a statement that was read at the ceremony.
"China is so lucky to have so many beautiful animals to represent the Olympic spirit," Rogge said.
The animals were introduced as Bei Bei, Jing Jing, Huan Huan, Ying Ying and Ni Ni - which, put together, translates to "Beijing welcomes you!"
Previous Olympic mascots
1972 Munich Games - Waldi, the first official mascot, was a Dachshund dog modelled after a longhaired breed of the species.
1988 Seoul Games - Hodori portrayed the friendly side of a tiger, which appears in many Korean legends.
1996 Atlanta Games - Izzy was an abstract fantasy figure, whose name was derived from "Whatizit?" as no one seemed to know exactly what Izzy really was.
2000 Sydney Games - Ollie the kookaburra, Syd the platypus and Millie the echidna were three native Australian animals chosen to represent the earth, air and water.
It is the most number of mascots any Olympic Games has had in more than 30 years. The Salt Lake City and Sydney Games both had three.
A plethora of real and mythic creatures were among the candidates considered by Chinese leaders, Olympic officials and design specialists over the past year.
Among those that did not make the cut were the dragon and a mischievous magical monkey out of Chinese folklore.
Multiple mascots are not uncommon. The 2000 Sydney games had three native Australian animals and two years later in Salt Lake City a hare, coyote and bear represented the event.
Animals have proven to be popular choices as symbols of local culture, if not athleticism, from Vucko the wolf at the 1984 Sarajevo winter games to Cobi the surrealist dog, who represented the 1992 Barcelona games.
The selection of China's mascots generated plenty of debate, and caused headaches for a design team trying to select something that could best represent a country which has a written history going back more than 2000 years and much tradition to draw on.
At stake for China is one of the most marketable symbols in the Olympics - a symbol that stands to generate significant revenues and public support for the Beijing Games, which will cost an estimated $38 billion.
Sales of licensed products, including those with the mascot, have brought in about $300 million at the Sydney and Athens Olympics. Host cities keep 10 to 15% of the royalties, helping to defray the costs of staging the games.
Multiple mascots for the games
are not uncommon
Officials with the Beijing Organising Committee for the Olympic Games say they expect sales of such products to be higher still.
To capitalise on the mascots' publicity, Beijing is launching an extensive marketing campaign.
An animated film put together by Han Meilin, who headed the design team, was screened at Friday night's unveiling and is expected to be replayed on Chinese television in coming days.
"This time the mascot design fully combines traditional Chinese culture," Han was quoted as saying by the Chinese website, Sina.com.
On Saturday, postage stamps and more than 300 other licensed products of the mascot go on sale at 188 authorised venues across the country, widening a product line of T-shirts, caps, pens and bags bearing the 2008 Games logo, according to Olympic officials.
To capture an entire range of consumers, the mascot products will range from fluorescent pens for eight yuan ($1; 85 euro cents) to souvenirs made from precious metals selling for tens of thousands of yuan (thousands of dollars or euros).
Beyond the sales expectations, China has tried to use the mascot-selection process to involve communities far from Beijing. On hand for the unveiling at the Workers Gymnasium in eastern Beijing were 100 children "ambassadors" from western provinces.