The LPGA's leading money winner this year, popular rookie Nancy Lopez, does something interesting in her hotel room at night. She cries.

"I cry sometimes at night because I feel alone," said Lopez. "Sometimes, I get sad. My mother is gone (She died a few months after Lopez dropped out of college to join the pro golf tour). I'm not with my boyfriend (they recently broke their engagement.) And my father is far away.

'My mother always felt sorry for me after I joined the tour. She knew it was hard to be alone. I feel now is a time I should talk to my mother.

"When I feel like this, I don't feel like I can call anybody. I don't even feel my best friend would understand."

Probably not. Her best friend became a secretary and settled in Dallas. Lopez became a star and hit the road. Their lives are very different now.

"It's not as glamorous as it looks," said Lopez. A few moments earlier she had described her life as "exciting, a great experience," and she meant it. But the tour disguises a ferocious Mr. Hyde within its enviable Dr. Jeckyl.

"We shouldn't be envied. There is so much pressure and traveling. I feel so much older than 21," said Lopez. "You really have to be a strong person to do this."

The approximately 150 women regularly on the LPGA tour have lives completely different from anyone else's for two reasons:

They travel 11 months of the year, greeted in city after city by the too familiar faces of one another and usually no one else. Family life is inconvenient at best. Wallet photos of children are rare commodities on the tour.

Their weekly paychecks vary from zero to five digits, depending on a seven-foot putt here, a lucky chip shot there. Lopez won $22,500 for her victory in the LPGA Championship yesterday. But seven players survived the cut only to go on to make nothing. Four others took home only $75 for their efforts. Lopez probably is not the only one shedding tears at night.

These are the rules of their game, and within these boundaries, they all play differently. No one picture could be painted to represent them all, the following are a few scenes stolen from the unusual gallery of LPGA life.

"I don't like being surrounded by women," said Karolyn Kertzman.

Laughing intermittently, Kertzman rattled the ice cubes in her cocktail glass and peered at the party in the adjoining room through blue tinted glasses. It was a lively bash with all the trimmings - a band, a banquet spread of cold meats, fruit, hot dogs and shrimp, and plenty of drinks. The guests were tournament sponsors, various VIPS connected with the recent Baltimore Open and however many golfers tour publicist Chip Campbell could coax into attending. There is a party like this before almost every tournament, and after a while they are all alike.

"I don't know anyone in there," said Kertzman. "It's the biggest bore in the world But it's my job."

Kertzman is about as understated as her Farrah Fawcett-arranged red hair. She says what she thinks, and she thinks most women golfers are suffocating imprisoned by the tour.

"I don't know them and I don't want to know them," said Kertzman. "I really feel sorry for a lot of the girls. They've been hitting golf balls since they were kids and golf is number one, with everything else second.

"The tour is very cliquish. No one talks to Carole (Jo Skala) and I. We cook and clean house, and some of these girls don't know that that is.

"To me, it's a job, not a lifestyle."

Kertzman's best year was 1976, when she won $13,914.25; her highest finish, third in the 1975 Wheeling Classic. Later that year she injured her back in a car accident and, she says, she is just now getting back to full strength.

Since her marriage last October, in which the former Richard Hansard took her last name, Kertzman has reorganized her travel schedule into a series of one-month trips instead of the three-month hauls she frequently went on when single.

"I used to go through men like you wouldn't believe," said Kertzman. "I dated a lot. I was foot loose and fancy free. I called the shots, which I hated.

"But after a while, they'd say, 'When we get married, you'll quit the tour.' That happened so often it wasn't funny. It got to the point where I was really down on the male ego.

"I knew what I wanted in a man and Richard had it. I wanted a man who will let a woman be herself and won't feel inferior or superior to her.

"We don't ever fight. We ask ourselves, 'Is it really worth it to fight when I'm leaving in a week' We're together a couple weeks. Then I leave and it freshens the air. It's a great life style.

"A lot of people think he must be some kind of wimp to take my name. No way. Richard (a promotions manager for a Sacramento newspaper is stronger than any man I know. It was his idea. He said for me to take a new name would be like starting all over as a rookie. And it we put our names together, it would go all the way around the golf bag.

"Richard is totally liberated. And you know what's amazing. He's good looking."

It was near closing time at the Pine Ridge Country Club golf course, and the only other people left in the clubhouse - an attendant and a writer - began to wonder if tour sex symbol Jan Stephenson might need some food and water brought to her telephone booth. After 75 minutes she emerged, wondering where she had left her pouch of jewelry.

"I am dead," said Stephenson, dropping into a seat and apologizing for the delay. "I dream about having a 9-to-5 job. I'd love to stay in one place and see how I like it."

Perhaps the main thing these golfers have in common with the rest of the world is the endless curiosity about how the other half lives.

When the putts stop falling and the pay phone has swallowed her last dime, a woman golfer longs for a bottle of Lysol and the three-bedroom house that goes with it. But in reality, many of these competitive women would waste away in a suburban family setting.

"I'd probably get restless," Stephenson said.

Stephenson had just arrived at the tournament that day after a 2 a.m. fishing excursion. She had been playing at Hilton Head. Leading her gallery was a new friend, Steve Bartkowski, the Atlanta Falcons' quarterback.

"It was so much fun," said Stephenson. "We'd go with some friends to the practice green (after her round) and putt until dark. We'd go to the beach and go swimming. It really did help to have him there."

Stephenson won at Hilton Head - her first tour victory this year.

Even for Stephenson, who is as pleasant as she is attractive. "It is difficult to get relationships going."

This is a mystery to anyone who has seen Stephenson but is not aware of the life of a professional golfer.

While women are more accustomed to making sacrifices for a traveling husband, a man almost inevitably requests the woman quit the tour. That is why life on the women's tour is so basically different from the men's. Most of the women are single; most men pros are married.

"The men have their wives travel with them," said Stephenson. They aren't as close to each other as we are."

One golfer said she didn't like the implications of having so many single women on the tour who are such good friends. "I would like to see a Mrs. in front of every name," she said.

If the women golfers tend to seek one another for relationships, friendship, support, advice and fun it is apparently because, in their helter-skelter life, it is probably more convenient than establishing a rapport with a man, who must be left behind in three days anyway.

Most of the single golfers interviewed said they would like to be married but that it hasn't worked out yet. Stephenson was married in her native Australia for less than a year before joining the tour. She would like to give marriage another try.

"You would have someone to go home to, and golf wouldn't be everything," said Stephenson. "If I played bad. I wouldn't think it was the end of the world. That's why a lot of the married girls do so well."

There is a cause and effect question involved with single women on the tour. Do single women gravitate toward the tour? Or does the tour almost dictate that women remain single? Stephenson says that she has seen herself change in the five seasons she has played in the LPGA.

"I can see a difference in myself. My second year on the tour, for example, my clubs were stolen and I called my parents and cried. I said I'd never play again," said Stephenson. "I've lost three more sets since then. Now I just call up and re-order the clubs and think nothing of-it.

"We are very independent. We are so used to making flight reservations, changing them, getting hotel rooms, making decisions. The trouble where men were concerned is that you've gotten to where you tend to want to do everything yourself, and it puts them off.

"We are so strong, in so many ways. I hate to see housewives be too dependent, be unable to handle things, reply on their husbands to make all the decisions. I don't like to see women do that."