At least 400 Northwestern University students and faculty have signed newspaper advertisements protesting the university's intention to award an honorary degree to Israeli Prime Minister Menachem Begin this week as part of a program marking the 30th anniversary of the Jewish state.

The campus newspaper. The Daily Northwestern, carried an editorial branding the award as a "blatantly political act." The editorial charged that the degree is being awarded because the university was criticized last year for failing to take a position against a book by faculty member Arthur Butz contending there was no Nazi policy to exterminate Jews in World War II.

Ads protesting the Begin degree appeared every day last week in the student paper.

One ad, signed by 73 faculty and more than 200 students, identified Begin as a leader of the Irgun raid on the Palestinian village of Deir Yassin, in which an estimated 250 to 350 civilians were killed April 9, 1948.The ad objected to the awarding of the degree because of "the apparent absence of any academic or other appropriate achievement in Mr. Begin's career" to justify it.

Another ad, placed by the African Students Association, expressed opposition to the "Israeli militarist state and the Zionist doctrine on which it is based, which bear a striking resemblance to the racist regime of South Africa and its ideology of apartheid."

Other ads were purchased by the Arab Students Association, the Iranian Students Association and a group of graduate history students.

The B'nai B'rith Hillel Foundation and Organized Jewish Student Community at Northwestern have reserved space this week for ads defending Israel as "the only free and fair society in the Middle East." But the planned ads do not directly defend the awarding of the honorary degree.

A public protest is planned outside the hall where Begin is to accept the honorary Doctor of Law degree Wednesday night from university President Robert H. Strotz. The university's official spokesman estimates that 200 to 300 people will protest, but the demonstration's planners say the total will be larger.

Strotz contends that the awarding of the degree "is not taking a political stand. It does not mean the university is endorsing the person's opinion on anything at all."

Thomas G. Ayres, chairman of the university's Board of Trustees, which approvel the award, denied that the Butz book had only bearing on the decision to award the degree.The award was made, he said, because "Mr. Begin is the head of a very important state."

A student-faculty protest also is devoloping at Indiana University in Bloomington, where an honorary degree is to be awarded next Sunday to H. Kamuzu Banda, president of Malawi, who attended the university in 1928-29.

Amnesty International, the Nobel prize-winning human rights organization, reported two years ago that there were more than 1,000 political prisoners in Malawi and that alleged human rights violations had been committed against the African nation's indigenous Jehovah's Witness population.

"If he is trying to rehabilitate his image by coming here, he's not going to succeed because he's going to get some very unfavorable attention," said Robert V. Arnove, an associate professor of education and the leader of the Bloomington protest.