BOMBAY - The day breaks over a parking lot here, and the homeless stir. Piles of rotting fish, heaped on a nearby dock, emit a putrid stink. Through the riot of horns and smog that accompanies Bombay's morning traffic comes the sound of laughter.

"Hahahaha!"

"Ho-ho-ho-ho!"

"Aaaaaahh-hahahahaha!"

The Jogger's Park laughing club is flooding the air with its humorous intent: the gut-busting laughter of a hundred Indians. In parks and parking lots across India, men and women, doctors and shopkeepers, teachers and clerks are coming together to begin their day with 20 minutes of forced guffaws.

Equal parts mysticism and Marx Brothers, India's laughing clubs have become a national phenomenon, offering their mostly middle-class members a moment of joy in a country shot through with sadness.

"No one ever laughs in this country," said Pushpa Goenka, a social worker and laughing-club devotee. "We see a lot of misery here. If I start my day with a laugh, my whole outlook changes."

The clubs have prompted some observers to discern the beginnings of a shift in the Indian psyche. In a country where comedy clubs and stand-up comedians are rare, groups dedicated to laughter might change India for the better, they say.

"We are a singularly humorless nation," said Khushwant Singh, a journalist and author who has written five humor books. "There are too many sacred things here . . . Perhaps if people are seen making fun of themselves, then other people will decide that's OK."

The laughing clubs' catalyst was Madan Kataria, a jovial Bombay physician and yoga enthusiast. Three years ago, he and four friends stood in a circle in Lokhandwala Park and shared a laugh. Almost immediately, he says, other people began turning up. Today, the club has about 100 members.

Kataria says he receives calls and letters daily from people wanting to form clubs. In Bombay alone, there are 50; in Calcutta, 24. He is convinced that India, for all its problems, could stand to lighten up.

"We Indians are a very serious people," said Kataria, whose face is free of expression lines. "I'm attempting a social transformation."

Kataria came up with the idea after reading "Anatomy of an Illness" by the late Norman Cousins, who found that laughter helped ease the painful symptoms of his arthritis-related disease.

When Kataria and his four friends first got together in March 1995, they told jokes. After a month, Kataria said, their club had grown to 50 people, but the jokes had grown stale. Some people - such as women and Sikhs, the butt of many standard Indian jokes - were offended.

So Kataria and his friends decided they would just laugh outright, unprompted by jokes.

One recent morning, the Jogger's Park club began with deep breathing, then a warmup in which everyone shouted, "Ho-ho, ha-ha! Ho-ho, ha-ha!"

Then the hard-core laughing began, with seven different laughs: the "hearty laugh"; the "silent laugh" ; the "closed-mouth laugh"; the "dancing laugh"; the "swinging laugh" (laugh twice quickly and then once at great length); the "one-meter laugh" (laugh while measuring an imaginary object 1 meter long); and the "cocktail laugh" (mix the laughs together).

By the end of the session, everyone appeared flushed, happy and relaxed.