Republican candidates have the edge in fund-raising in four key Virginia state legislative races, giving them a better shot at financing a last-minute campaign blitz in the 16 days until the election, according to finance reports filed yesterday.

State Sen. Jane H. Woods and Del. Jeannemarie Devolites, two GOP incumbents, have raised twice as much money as their Democratic opponents. And two Republican challengers, Scott T. Klein and Thomas M. Bolvin, are holding their own against better-known Democrats.

Leaders of both parties are closely watching all four of the Northern Virginia races because they could hold the key to partisan control of the state legislature.

An unprecedented amount of money from the national Republican and Democratic parties has been pouring into these four races because party strategists know that the party in control after Nov. 2 will redraw the boundaries of state and local districts after next year's census.

"The Republicans in general have more money this year than they've ever had in General Assembly races," said Robert D. Holsworth, a professor at Virginia Commonwealth University. Until this year, he said, "they've never had a financial advantage in General Assembly races versus the Democrats."

The most frantic money chase is between Woods and Democrat Leslie L. Byrne, a former state delegate and member of Congress. Together, the two have raised more than $650,000 in their fight to represent central Fairfax County's 34th District in the state Senate, an unprecedented amount for a state legislative race in Virginia.

Woods is winning the financial race.

The two-term incumbent has raised about $423,000--almost twice as much as Byrne's $228,210, according to yesterday's reports. Even more important for the final days of the campaign, Woods reported having about $125,000 left to spend, far more than Byrne's reported $55,000.

Byrne campaign manager Robert Becker brushed aside the difference, saying he is confident Byrne will be able to match Woods when it comes to sending mailings and other advertising during the final stretch.

"We're right where we need to be," Becker said. "I have a great deal less overhead than the Woods campaign. We are very competitive in communication dollars."

Byrne's campaign has benefited from tens of thousands of dollars in contributions from organized labor and the national Democratic Party. But even those large contributions are being shadowed by the donations by national Republicans.

Holsworth said U.S. Rep. Thomas M. Davis III (Va.), the head of the Republican Congressional Campaign Committee, has put more than $250,000 in the races "and by all indications plans to put in up to half a million dollars."

Davis said, "This is the first time the Republicans have outspent the Democrats" in Virginia election campaigns. He also asserted that Republican candidates for the first time were "out-organizing the Democrats" at the grass-roots level.

A major beneficiary of Davis's largess is Klein, who is running for a vacant House seat in the Mount Vernon area against Kristen J. Amundson, a better-known Democrat. Klein has raised nearly $168,000 and has more than $45,000 left, while Amundson has collected $115,000 and has $29,000 remaining for her stretch run.

Among the big contributors to Klein in the past month has been the Commonwealth Council, a political action committee led by Republican Gov. James S. Gilmore III, which has kicked in $75,000.

Devolites has also received money from Davis in her bid to be reelected to the 35th House District in and around Vienna. Devolites has raised $162,762, compared with her Democratic opponent, George Lovelace, who has raised $81,315. Devolites also has more cash on hand: about $53,000 to Lovelace's $9,000.

In the 43rd House District in the Franconia-Springfield area, longtime incumbent Democrat Gladys B. Keating has raised about $150,000 and has about $90,000 left to spend. Bolvin, her Republican opponent, is close behind, having raised almost $140,000. Bolvin has about $45,000 left to spend.