In a letter to the New York Times yesterday, Professor Kenneth W. Colegrove of Northwestern University denied he had accused Rupert Emerson, professor of Government, of being a communist.

Colegrove reportedly testified last week before the Senate Internal Security subcommittee that Emerson, as well as Edwin O. Reischauer, professor of Far Eastern Languages, and John K. Fairbank, professor of History, had been associated with the communist party in this country. He did not depy mentioning Fairbank and Reischaur.

United Press dispatches said Colegrove had called Emerson a card holding member of the party. Emerson wrote a letter to Colegrove as soon as he heard of the charges, denying them and expressing surprise that the Northwestern professor could so testify. He said further that records would show he had never attended the conference referred to in Colgrove's testimony.

Last night, Emerson said he had not yet heard from Colgrove and did not know that the correction had appeared in the Times.