Dr. William H. Rumsey, director of the Department of Recreation for the District of Columbia, said yesterday that plans are under way for a District of Columbia Marathon to be held next spring.

"It's even money that we will have one, regardless of its size," he said.

The fifth annual Marine Corps Marathon, scheduled Sunday morning, is the only marathon now run in the District. More than 8,900 runners are entered in the race, which begins at the Iwo Jima Mermorial at 9 a.m.

Unlike the New York City marathon run Sunday, the Marine Corps Marathon is a race geared primarily for local runners (69 percent of the field comes from within a 200-mile radius) and first-time marathoners (35 percent). The marines, who cannot pay expenses to bring in big-name runners or accept donations from corporate sponsors, say their race is intended to promote physical fitness, not the glitzy, big-money side of long-distance running.

Rumsey envisions a major marathon in the District, "with the top people from all over the world."

"I'd want (Bill) Rodgers here," said Rumsey, who also is the head of the mayor's task force on special events. "I'd want that fella who won in New York (Alberto Salazar) here. We may not get the top names the first time. I'm not naive enough to think that we'll have a fantastic biggie the first time."

Rumsey said he was thinking in terms of a race subsidized by outside corporate sponsors capable of providing the money necessary to attract top runners, tied thematically to the city's historical monuments.

"The money is in private industry, which can afford and would be interested in a Nation's Capital narathon, especially if it had a theme," he said.

"IBM and Xerox, those are the people we have talked about approaching," he said.

Asked if he had approached Mayor Marion Barry for his support, Rumsey said, "I've mentioned it to him casually. He is usually receptive to our innovative ideas."

Alan F. Grip, press secretary for the mayor, said, "I don't think the mayor would have a problem in the world with it, if it is put together properly and I have no doubt that it would be."

The race of Rumsey's dreams would differ significantly from the one staged by the Marine Corps. Ironically, at a time when the attention of the long-distance running community is focused on the issue of going professional, the Marine Corps Marathon comes as close as any race in the country to being a purely amateur event. The marines say there is room for both kinds of races in the country. Whether there is room for both in one city is another question.

Jeff Darman, an executive of the 10-mile Perrier Cherry Blossom, said, "We don't need two full marathons within four months of each other. It would put a tremendous strain on volunteer resources, as well as police and other city resources, especially if it was held around the time of the Cherry Blossom (April 5, 1981)."

The marines, whose race income is generated solely by entry fees ($7.50 each) are accustomed to strained resources. According to Capt. Jay Paxton, this year's race coordinator, the budget for the race will be $72,500, if 10,000 enter. Marine Corps regulations require that all the money be spent on the race (last year $3,000 remaining after the race was used to purchase materials for 1980) and that none of it may be spent on providing expenses for runners. They won't even pay fees for guest speakers, such as author Jim Fixx, this year's guest.

"We don't have to worry about The Athletics Congress and what's legal as far as amateurism goes," said Paxton. "If someone told me that Bill Rodgers would come down for air fare and $100 a day, I'd have to say, 'Thanks but no thanks.'"

The financial limitations have in large part determined the character of the race.

"There is a purity to an amateur marathon and we're proud of it," Paxton said. There are those who believe the Marine Corps Marathon suffers in comparison with Boston and especially New York, coming exactly one week after the Big Apple extravaganza. As one East Coast race director put it, "It is what it is: olive drab, just like the military."

But others disagree.

"I hope there always is a place for the Marine marathon," Darman said. "It really is designed for Joe Average Runner. There is nothing wrong with it. It's just different in this day and age."

Still, the marines understandably are a bit frustrated, and a bit bewildered, by the reception the race has received. They view it as a public service as well as a public relations vehicle for the service. Last year, Washington residents did not exactly storm the barricades to watch the runners go by. "It is confusing," Paxton said.

There are several explanations.

"It's not Boston because it doesn't have the years of tradition," Darman said. "And it isn't New York because they don't spend the money to bring in the national and international field. And unlike Boston and New York, it doesn't have the enthusiastic crowds. Partially that's because Washington thinks of itself as so sophisticated it can't get excited about a marathon. Partially it's because only a small portion of the route goes through residential areas. The 9,000 spectators are all in it."