Cameron said the attractions based on the top-grossing film of all time would bring the lush, bioluminescent planet of Pandora to life and would include animatronics and 3-D and holographic technology.
Fans of the film have said they wanted to visit Pandora, he said.
"The scenes that people liked best were not the obvious things like the big battle scenes," Cameron said. "It was the creatures, it was learning to fly, it was being in the forest at night.
"So here's an opportunity ... to bring this world to life and get you to wander in it and see things you didn't see in either in the first film or the subsequent two."
Cameron is working on the second and third installments of "Avatar," to be released in December 2014 and December 2015. The park will include elements of the second and third films and elements that aren't included in any of the films.
The first installment of "Avatar" was a 3-D movie about a race of blue-skinned Na'vi who defend the moon they live on from invading humans. It has grossed about $2.8 billion in theaters worldwide since its December 2009 release and has brought in many millions more from home video sales.
News Corp.'s Twentieth Century Fox, the studio that distributed "Avatar," also is a partner in the theme park and will distribute the next two films.
It's not unusual for Disney to partner on projects that weren't produced at its own studio. It opened an "Indiana Jones" attraction at Disneyland in 1995 in partnership with Lucasfilm even though the film was distributed by rival studio Paramount, which is owned by Viacom Inc.
Disney CEO Bob Iger said the long-term agreement includes the possible expansion of "Avatar" to Disney's other parks worldwide, but there are no immediate plans to do that.
Cameron, his company, Lightstorm Entertainment, and producing partner Jon Landau will not get a cut of theme park ticket revenues. But they will help develop the area under a licensing deal that includes royalties on food and beverage sales, Staggs said. The area should help create thousands of jobs, he added.
Walt Disney shares closed down 20 cents Tuesday at $32.31.