Rep.-Elect James P. Moran Jr. and the man he defeated last month, Rep. Stan Parris, spent more than $1.8 million on their bitter campaign in Virginia's 8th Congressional District, making theirs one of the most expensive House races in the country.

Moran, a Democrat, and Parris, a Republican, spent more than $900,000 apiece in their high-profile contest, and Moran ended the race almost $100,000 in debt, according to campaign officials. Under federal law, candidates for the House and Senate were required to file their first financial disclosures since the Nov. 6 election yesterday.

In other Washington area races, Maryland Rep.-Elect Wayne T. Gilchrest (R) finished his successful campaign to unseat Democratic Rep. Roy P. Dyson about $25,000 in debt, campaign officials said. Gilchrest raised more than $250,000.

D.C Del.-Elect Eleanor Holmes Norton (D) raised $417,000, campaign officials said, and owes $62,000.

Several of the area's House incumbents easily won reelection and will begin the 1992 election cycle with six-figure treasuries left over from this year's campaigns. Among the leaders are Maryland Democratic Reps. Tom McMillen, who has $374,000, and Steny H. Hoyer, who has $334,000.

But the area's largest remaining treasury belongs to Sen. John W. Warner (R-Va.), who faced token opposition and who has more than $640,000 in the bank. Warner could use that money to repay himself $400,000 in loans he made to his first campaign in 1978. He said yesterday he will make no decision on that until next year.

According to Common Cause, a group that tracks campaign finances, the Moran-Parris race almost certainly will be among the country's 10 most expensive House races this year. As of Oct. 17, the last time congressional candidates filed financial disclosures, their campaign ranked seventh on the money list.

The two spent about $700,000 in the last two months. "This campaign is up there," said Jackie Howell, a Common Cause spokeswoman. "It's a remarkable amount."

Moran's debt, $98,700, is larger than the entire budget of most Washington area congressional challengers. But Kathy Lash, Moran's press secretary, said Moran does not expect to have trouble balancing the books.

"The debt is actually smaller than we had expected," Lash said. "We've had a lot of unsolicited money coming in since the election, and we haven't done any organized fund-raising. We think we'll be able to deal with it all right."

Moran's largest creditor is Alexandria media consultant Joe Trippi, who agreed to work without a salary and for a contingency fee if Moran won. That fee is $25,000. Moran also must repay two national Democratic Party organizations that loaned him $15,000.

In Maryland's 1st District, which covers the Eastern Shore and Southern Maryland, Gilchrest raised more than half of his money after Oct. 17, as his campaign to unseat Dyson surged. Of his $255,000 in total contributions, $131,000 has come since that date. Aides to Dyson declined to discuss his campaign finances yesterday.

Gilchrest's latest financial disclosure shows a $5,000 surplus, but aide Mary Larkin said yesterday that Gilchrest expects about $25,000 in miscellaneous expenses for his transition office. "It's not a huge amount, and we don't expect a problem," Larkin said.

Donna Brazile, an aide to Norton, said her campaign debts include a $20,000 personal loan from Norton and more than $20,000 in fees to campaign strategists.

Warner raised about $1.3 million for his Senate bid, much of it before Democrats announced they would not nominate anyone to oppose him. Warner said yesterday that "there may be some pay-down" of his debt from 1978, but that "I really haven't spent time thinking about it yet."

Several House incumbents in Virginia and Maryland will begin the 1992 election cycle with financial advantages over any challenger. Many incumbents want to protect themselves when congressional districts are redrawn next year.

Brad Fitch, a spokesman for McMillen, said, "You have to be prepared for any consequence that might occur."