Virginia Lt. Gov. Charles S. Robb said today a $2,500-a-person legislative reception at his McLean home later this month "is not a shakedown" and has no connection to his expected race for governor.

Robb told a news conference that published accounts of the reception, part of a two-day Northern Virginia tour for the state legislators, were "erroneous" and "misleading." He did not dispute, however, the $2,500 contribution price established for business people who wish to attend the event at his home.

"It is simply a reward set up so that those who were particularly generous could be included in some of the social events," he said. The contributions will pay the costs of the $70,000 tour.

Appearing at a press conference to announce the agenda for the tour, Robb also rejected suggestions that his involvement in the project was an effort to boost his political fortunes in advance of this fall's race for governor. "Any time that you can increase understanding it can be helpful, but it's not designed for the purpose," he said.

Robb, a laywer and son-in-law of the late President Lyndon B. Johnson, is expected to face Virginia Attorney General J. Marshall Coleman, a Republican, in the contest.

Organizers of the tour, which is aimed at acquainting downstate legislators with the problems of the populous Northern Virginia suburbs, said Robb's expected candidacy earlier had snarled plans for the reception. "Some people thought it was political to have it at Robb's house, but we said he's the top elected official from Northern Virginia," said Robert L. Taylor, a Washington Gas Light Co. executive who is chairman of the tour.

"Then some people said we ought to have it at Coleman's house and we said that really would be political," Coleman lives in Richmond.

Included in the agenda for at least 100 touring Virginia legislators will be visits to Dulles Airport, the fast-growing Tysons Corner area in Fairfax, and the Upper Occoquan Sewage Facility. Organizers are also hoping that the legislators, who will travel Shirley Highway by bus during an evening rush hour on Jan. 30, will get a veiw of a typical Washington traffic jam.