In a town where simians stroll on the sidewalks and partake of Chinese banquets on red tablecloths, there's obviously no business like monkey business.

Just ask Lopburi's monkey magnate, Yongyuth Kitwatananusont, who's parlayed humankind's attraction for distant cousins into a multimillion-dollar business.Monkeys have been residents of this onetime royal seat for centuries. In recent times, some 2,000 of them have been hanging out on the grounds of an ancient temple and nearby streets. They've taken well to urban living.

The clever macaques clamber up fire escapes, use power lines as aerial walkways, relax on people's balconies and walk into food stores hoping for generous, or inattentive, shopkeepers.

Residents say some monkeys will hop on passing railroad cars for extended journeys, but they always return home to their primate paradise.

Yongyuth also found Lopburi, about 95 miles north of Bangkok, to be the promised land.

The son of Chinese immigrants who came to Thailand without a penny, the family was beset by troubles and poverty until it moved to the town, where monkeys are said to bring good luck to those who treat them kindly.

The 53-year-old entrepreneur, who now owns three hotels, a shopping plaza and is planning a golf course, ascribes his turn of fortune to the animals.

So about six years ago, he hit upon the idea of an annual "thank you" feast. It started small, but the sixth one, held in November this year, attracted thousands of tourists as well as troops of simians who descended on tables covered by tablecloths and laden with food carefully arranged on bronze trays.

Bill for this bounty of fruits, vegetables, boiled eggs, nuts and sweets came to some $50,000, but that's peanuts for Yongyuth.

"If I pay respect to the monkeys, business always turns out very good," he said with enthusiasm. "Before, you would get a few tourists coming to look at our old ruins. Now there are thousands, Thais and foreigners, coming because of my monkey promotion."

And many stay at his hotels, where tables, lamps, paintings and statuary feature, naturally, monkey motifs.

By 2000 Yongyuth plans to have the world's largest monkey theme park on 40 acres he's already purchased. Besides his beloved macaques, there will be research materials, films and educational displays as well as 28 12-foot high statues of real and mythical monkeys.

Some have already been finished, including one of Waeng, the unrivaled, 20-something leader - "mafia boss" Yong-yuth calls him - of the Kala Temple monkey troop. The businessman "consults" with Waeng before each monkey feast.

Battle-scarred from past, unsuccessful power grabs by rivals, Waeng lords it over hundreds of followers who get plenty of food from temple keepers and tourists. Within the temple enclosure, they are able to snatch sticks of incense, plastic bags and an occasional camera from visitors for playthings.

Their only problem seems to be the town gang, the monkeys who opted for street life. Yongyuth said the two troops rarely meet without a fight, and he has a major problem each year trying to get both to sit down together amiably at his banquet tables.