Sen. Charles McC. Mathias (R.-Md.), supported by a score of legislators from both parties, introduced legislation yesterday to set aside a two-acre section of Constitution Gardens for a Vietnam memorial.

Jan C. Scruggs, a veteran of the Vietnam war and now president of a memorial fund to raise private donations for such a monument, said that when he came home in 1970 there were no parades, no bands and "being a verteran of that war was a dubious distinction at best."

Nearly a decade later, Scruggs is campaigning to end "the sharp division in our generation" created by an unpopular war.

The new legislation would enable Scruggs' fund to build a memorial on the Mall inscribed with the names of the 57,414 Americans who died in Vietnam.

Scruggs, 29, an equal employment opportunity specialist with the Labor Department, said, "It is especially appropriate that this monument stand in Constitution Gardens in the shadow of the Lincoln Memorial. President Lincoln many times spoke of his concern for the reconciliation and reunification of our country after the Civil War. Although the circumstances were different, certainly the need for unity after a divisive war is just as great . . .

"About 90 percent of the men I served with were drafted to do the fighting in that unpopular war. Yet, if the war was unpopular at home, it was probably liked even less by those who were on the front lines," he said.

The memorial fund was organized last April "to be a symbol of reconciliation of our nation's determination to restore the unity that existed prior to Vietnam," Scruggs said.

Mathias, noting that his legislation was introduced three days before Veterans Day, said the memorial "will provide a long overdue acknowledgement by the American people of the sacrifice and service of Vietnam veterans. It will contribute greatly toward resolving the real and continuing divisions in our society as a result of that war."

Sen. John W. Warner (R-Va.) said he has offered to help conduct the fund drive which will seek $1 million to $2 million "from a lot of people, but not a lot from any one."

Mathias said the resolution could pass Congress in this session, and the memorial could be built in two to five years, depending on how soon the money is collected.