Freshmen, sophomores and juniors now must sign a loyalty oath to belong to the Harvard Army ROTC program as a result of tightening in the Army's security regulations.

The loyalty oath, which asks the student to deny membership in the Communist Party and its fronts, will also be employed by the Air Force units here in the next few weeks.

The oath resembles a form administered to all former ROTC members when they apply for commissions after graduation. The standard form for any commission, this marks the first time it has ever been signed by students.

The new loyalty oaths will be signed sometime early this week, as part of a nationwide program. The oath names every organization on the Attorney General's subversive list, and asks the cadet or prospective cadet whether he has ever been a member of any listed organization. All Army oaths will have to be signed in the presence of Captain Roy G. Simkins, Jr.

If the person refuses to sign the oath he can not become a member of the unit, while if he checks off membership in any of the organizations his papers will probably be sent to First Army headquarters for further checking.

"Violent" Reform

It is believed that the document will also contain a clause stating that the student has never condoned or aided any "violent" economic or political reform.

Captain Simkins, speaking for himself, last night termed the new restrictions "a result of the trouble the Army has had over security, as seen in the recent television investigations and Senator McCarthy's investigations." He added that it was just one change in the Army's security system.

The new order was the result of a Congressional directive.