In this quiet commuter community, about 25 miles northeast of Manhattan, is one of the most famous and enduring amusement parks in America --Playland.

But in recent years, the 54-year-old park, which covers 278 acres, has been plagued by modern-day maladies. As a result, this year the county government decided Playland needed professional management and after an extensive search hired the Bethesda-based Marriott Corp. to turn the old park around.

Marriott got into the theme-park business in 1976, when it opened two parks --in Santa Clara, Calif., and Gurnee, Ill., between Milwaukee and Chicago. In 1980, Marriott's theme-park division, which is based in Santa Clara, reported sales of $84.8 million, about 5 percent of the company's total sales, and operating profits of $16.6 million, or 8.6 percent of the company's total.

Marriott has a two-year contract to manage Playland, and the park has presented some unusual problems. Located on Long Island Sound, Playland is a throwback to simpler times. Its architecture is delightfully dowdy art deco, and generations of Westchester County families have changed their clothes in its famous bathhouse before plunging into the Sound or the pool, strolled the boardwalk, played in the arcades and thrilled to a variety of rides.

Indeed, some of the same rides that were considered the last word in the summer of 1928, such as the wooden-frame Dragon Coaster and the Derby racer with its thundering horses, are still popular attractions.

But in recent years, Westchester County -- the richest in the state -- found that groups attracted by the free-admission policy would stake out territories in the park, set up grills, and stay there from opening to closing, eating and drinking -- but not spending.

In addition, the park's traditional family atmosphere was being threatened by groups of toughs. "There was tremendous vandalism and fights," says David Tooley, assistant to County Executive Alfred Del Bello. What's more, the county found itelf running a park that regularly violated its own health and safety standards.

Marriott, which was formally awarded the contract in April, managed to paint the park by opening day. Since then, says Robert Schafer, the 33-year-old park manager from Marriott, the company has refurbished restaurants and upgraded the food using its catering division. Borrowing from its other parks, Marriott has introduced resident entertainers who perform in an amphitheater and has utilized the casino, which contains three ice-skating rinks, for entertainment extravaganzas that Schafer says have been extremely successful.

But the most momentous change came when, for the first time in its long history, Playland charged admission. By theme-park standards the fee was modest -- $1 for Westchester residents, $2.50 for nonresidents. Then, in another departure from tradition, Marriott changed the closing time from midnight to 10 p.m.

The changes were not totally successful. In fact, the closing time had to be rolled back to midnight after Schafer witnessed carloads of people arriving at the park in the evening, then drive away after seeing announcements of the early closing time and the admission fee. "You can't change years of behavior in just six months," Schafer says.

Partly as a result of the attempted early closing, plus the miserable weather on the July 4th weekend, attendance at Playland is down 25 percent from last year, but Schafer says "some of the loss in attendance is by design, in an attempt to get back to a family-oriented park."

Until this year, the operation of Playland had been overseen by a group of prominent citizens, with a resident manager running the park. According to Tooley, the park has been losing an average of $300,000 a year for the past decade.

Tooley's boss, County Executive Del Bello, a two-term Democrat who was first elected in 1973, has long favored bringing in private contractors to run county services. For example, the county's buses are operated by private contractors. Tooley adds that since Pan Am recently took over operation of the county airport, the facility has gone from an annual loss of $100,000 to a profit of $250,000.

Last fall, when the county sought bids from contractors interested in running Playland, it got 16 formal proposals. These were narrowed to three: Herco Corp., the parent of Hershey chocolate; Radio City Music Hall Productions Inc., which runs the famous Manhattan theater; and Marriott.

Marriott was chosen after county officials toured the company's two parks. However, the citizens of Rye were not convinced Marriott was the right company for the job. Although they were unhappy with the deteriorating conditions at Playland, local residents also worried that their modest-sized park would blossom into a massive theme park.

In an effort to mollify the doubters, Tooley says he escorted a half-dozen residents of Rye, all of whom lived within 100 feet of Playland, on a tour of Marriott's Gurnee Park. According to Tooley, the Rye residents spoke with the mayor and other local officials and they randomly knocked on doors and interviewed Gurnee residents.

"Virtually every response was positive," says Tooley, who adds that the visiting group was "astounded by the cleanliness of the park."

Schafer says he still meets regularly with local citizens to listen to complaints and keep them abreast of developments at the park.

Marriott officials hope their two-year management contract will lead to a more permanent arrangement. The company collects a management fee of $300,000 for each year, plus 20 percent of the net revenues up to $500,000.

"It's an interim arrangement just to keep the park open," says Tooley, who knows that an advisory commission, with Marriott's help, is working on a master plan for updating Playland.