Virginia Democractic Party Chairman Joseph T. Fitzpatrick said today he has asked for legal opinions on the eligibility of Charles S. Robb to run for lieutenant governor because of questions raised about Robb's voter registration history.

The Virginia Constitution requires that candidates for lieutenant governor be residents and registered voters in the state for the five years preceding the date of the election.

The five-year period for candidates in this year's election began on Nov. 9, 1972. For more than 10 months after that date, Robb, son-in-law of the late President Lyndon B. Johnson, was registered to vote in Arlington but, according to public records and interviews with him, did not have a place [TAX OMITTED FROM THE SOURCES]

In order to be eligible to cast a balot under the state Constitution, a voter in Virginia must be registered and must have a "place of aboide" where he is registered. Fitzpatrick said in an interview that Sen. Joseph V. Gartlan (D-Fairfax) raised the fear in a recent Senate Democratic caucus that Robb's failure to meet this second test throughout the five-year period might open him t a Republican challenge of his eligilibility to run for office.

Fitzpatrick said, "We don't want a repeat of the Charles Ravenel situation that developed in South Carolina a few years ago." Ravenel won the Democratic nomination for governor, but was then ruled ineligible to run because he failed to satisfy residency requirements. His disqualification after his nominations led the election of a Republican governor.

As party chairman, Fitzpatrick must by April 20 certify all the Democratic candidates who file by April 15 to run in the June 14 primary. A ruling against Robb at that late date would be a stunning blow to the candidate.

Robb, 37, is making his first try for nation for about a year. Experienced Democratic campaign officials give him at least an even chance against his two opponents, Dels, Ira M. Lechner of Arlington and Richard s. (Major) Reynolds of Richmond.

They point out that he enjoys widespread name recognition because pf his White House marriage to Lynda Johnson, is putting together an ambitious campaign organization and apparently has solid financing.

When questions first were raised about his voter registration record more than two months ago, Robb dismissed them as "no problem." He added," I am satisfied that no court in Virginia would look at my residency and consistent voting record and disqualify me on such a technicality."

The questions about Robb's continuous valid registration arise from the fact that he and Mrs. Robb sold their Arlington home on Sept. 22. 1972. This left them as their only "place of abode" in Virginia a home they owned in Albemarle County near Charlottesville, where Robb attended law school from 1970 to 1973.

Robb said in an interview that he did not bother to change his registration to Albemale County "because we always intended to return to the Arlington area and assumed we could keep our voter registration up there."