Virginia's Republican state ticket, fresh from the party's nominating convention in Norfolk last weekend, arrived in Fairfax County yesterday to begin pursuing the voters of populous, politically crucial Northern Virginia.

"We understand the importance" of the region, proclaimed a smiling, jaunty Wyatt B. Durrette, the party's nominee for governor, in a crowded morning news conference at Fairfax County government headquarters. "It is more than symbolic that we begin our campaign here."

Durrette, appearing with his two running mates -- lieutenant governor candidate John H. Chichester and attorney general candidate W.R. (Buster) O'Brien -- and a host of local Republicans, scoffed at the likely Democratic ticket, which he said lacked a political base in Northern Virginia.

"I was working for funding for Metro before my opponent state Attorney General Gerald L. Baliles knew what it was," Durrette said. Baliles, who is expected to be nominated for governor this weekend by the Democrats, is from Patrick County, south of Roanoke.

Durrette began yesterday with 75 minutes of rush-hour glad-handing at Arlington's Ballston Metrorail station, followed by the news conference. He attended a luncheon in his hometown of Franklin, in Virginia's Southside, with former governor Mills E. Godwin, and was in Roanoke last night.

The three candidates will crisscross the state for the rest of the week.

Several times, Durrette labeled Baliles "a government lawyer for most of his career" lacking in leadership skills and called attention to his own experience as a businessman and attorney.

Responding to critics who have pointed out that the GOP ticket lacks a tie to Shenandoah Valley Republicans, moderates who once were a mainstay of the party's base in the state, Durrette noted that his mother is from Augusta County and his uncle is chairman of the Board of Supervisors there.

A Baliles-Durrette race would be a rematch of the 1981 campaign for state attorney general, which Durrette lost. Yesterday, Durrette blamed that defeat on a national recession and on what he called "ticket problems" -- an apparent reference to J. Marshall Coleman, the brash GOP candidate for governor who alienated some party members.

This year, Durrette predicted, the result will be different. He said he expects to receive hefty contributions from the national GOP -- though he declined to name a figure -- and looks forward to campaign swings by President Reagan.

Grinning broadly by Durrette's side were Fairfax County Board Chairman John F. Herrity and Northern Virginia Rep. Frank R. Wolf -- two Republicans who repeatedly make political mileage on the issue of transportation. Durrette insisted that the GOP slate "has more understanding of transportation problems than any previous ticket."

He said he supported increased funding for Northern Virginia roads and in particular backed the $200 million Springfield Bypass, the proposed Outer Beltway, increased rail transport and the completion of the 101-mile Metrorail system.

Durrette introduced Chichester, who was tapped on the fourth ballot late Saturday night after a pitched battle against Coleman for the lieutenant governor nomination, as "my right-hand man."

Chichester, a state senator from Fredericksburg, was applauded loudly as he stepped to the microphone. He pledged to campaign frequently in Northern Virginia.