Walt Disney World, citing the addition of several recently installed entertainment features, has raised its admission prices by 6 to 8 percent.

The increases affect all admissions - other than those limited to Florida residents - at Disney's Lake Buena Vista, Fla., complex.The standard single-day admission to one theme park (Magic Kingdom, Epcot Center or the Disney MGM Studios park) now costs $34.85, $27.45 for children under age 10, up from $32.75 and $26.40 respectively. (All quoted prices include sales tax.) The four-day passport, good for all three parks, is now $117.20, up from $109.85, and $92.90 for children, up from $87.65.

The five-day Super Passport has been increased to $153.15 and $122.50 for children, formerly $142.60 and $114.10 respectively.

The Super Passport, which represents a savings of more than $70 compared with single-day admisssions, is valid at all the theme parks as well as such additional attractions as Typhoon Lagoon, River Country, and Discovery and Pleasure Islands. The increases took effect last month.

Disney World, which last raised its admission prices in January 1990, is expanding its theme parks in preparation for its 20th anniversary celebration beginning Oct. 1.

Attractions added within the last year include the "Here Come the Muppets" and Teen-Age Mutant Ninja Turtles stage shows, the Sorcery in the Sky fireworks display and the "Honey I Shrunk the Kids" movie set adventure.

Florida residents can buy a pass called Four-Season Salute for $90 ($80 for children under 10) that gets them a day in the three theme parks in each of four of the less busy periods when children are at school. Its price remained the same.