BLACKSBURG, Va., Nov. 15— Virginia Tech has begun an investigation into whether a longtime professor for whom a dormitory was named was a student leader of the Ku Klux Klan a century ago.

An undergraduate class studying the 125-year history of Virginia Polytechnic Institute and State University found in an 1896 college yearbook a brittle, yellowed page devoted to the Klan. ''K.K.K.-1895-96'' reads the headline on page 101. Beneath a drawing of a skeleton covered by a white sheet, the group lists as its objective: ''To right the unrighteous.'' The favorite pastime is listed as ''(Midnight) field sports.''

Claudius Lee, a student, is listed as the organization's ''Father of Terror,'' founding leader of the campus Klan. Another student, O.M. Stull, is called ''Right Hand of Terror.'' The yearbook shows that Mr. Lee belonged to another campus group called the Pittsylvania Club, whose sketched logo depicted a black man hanging by his neck from a tree.

Mr. Lee went on to teach electrical engineering at Virginia Tech for 50 years. By the time he retired in 1946, he had been nicknamed the school's ''Grand Old Man.'' Virginia Tech named a dormitory for him in 1968, six years after his death at age 90.

Mr. Stull, as a student, coined the school yell, ''Hoki, Hoki, Hoki, Hy!/ Tech, Tech, V.P.I!'' from which the nickname for Tech students, Hokies, is derived. A former quarry company executive, he died in 1964.

''These are core icons of the school,'' said Peter Wallenstein, a history professor whose students found the yearbook. If the Klan material is true, he said, ''It's kind of ugly.''

The college president, Paul Torgersen, appointed a committee to look into the issue. ''It is regretful that this did happen, if in fact there was an affiliation with the K.K.K.,'' he said. At a meeting with students this week to discuss the discovery and incidents of intolerance on campus, Mr. Torgersen said that although the jury was still out on the nature of the yearbook material, ''When I first saw these pages I was sickened by them, and still am.''

Historians are unsure whether the yearbook page was a sophomoric joke or the record of an active group.

The Klan was founded in 1866 in Tennessee by Civil War veterans and quickly spread throughout the South, becoming a secret terrorist organization intent on keeping blacks and Republicans from gaining political power during Reconstruction.

Historians say the Klan disbanded by the early 1870's, not to be revived until 1915, when it broadened its activities to target Jews, Roman Catholics and foreigners, as well as blacks. The 1895-96 date of the yearbook raises the possibility that the Klan item was a prank. The Klan entry does not appear in other yearbooks.

''To the best of my knowledge, there's no Klan activity and there's no Klan in that era,'' said John Kneebone, a historian of the Klan in Virginia who lives in Richmond.

The students' designation of members as ''Angels of Terror'' is in keeping with the Klan's white-sheet symbolism, which sometimes represented the ghosts of Confederate dead, Mr. Kneebone said. But identifying members by name is ''very un-Klanlike,'' he said.

Family members, former students and colleagues who knew Mr. Lee and Mr. Stull said the two did not appear racist.

Bill Stull of Buchanan, Va., Mr. Stull's grandson, said: ''I never saw any evidence of that prejudice or anything. My gut feeling is he may have felt that way, but I believe he may have gotten over it.''

Black students who made the discovery were appalled.

''I honestly cringed when I opened the yearbook and it was there,'' said Cordel Faulk, a black senior in the history course. A white student, Geoffrey Buescher, who is also in the class, said he did not respond as viscerally as did black students like Mr. Faulk.

The committee -- Professor Wallenstein, a black studies professor and a black graduate student -- will try to find out whether the Klan group existed on campus and recommend possible responses, including whether to remove the Lee name from the dormitory.

''Even at that time, what the K.K.K. stood for was common knowledge,'' Mr. Torgersen said. ''Even if it was a joke, it was a very bad joke.''