For the second straight year a Harvard professor of government, who is considered one of the nation's leading political scientists, was denied election yesterday to the prestigious National Academy of Sciences (NAS).

The rejection by Academy members of Samuel P. Huntington, Eaton Professor of the Science of Government, culminates more than a year of debate on the scientific merit of Huntington's work and on the legitimacy of social science as a part of the the NAS.

Huntington received the necessary number of mailed ballots to be considered for election at the Academy's annual meeting, held yesterday in Washington. But at the meeting a challenge to his nomination was raised, and his election was blocked after a floor fight before 530 NAS members that one Academy member said went to the "bitter end."

Huntington's candidacy has been vigorously opposed by a group of Academy members led by Yale Professor of Mathematics Serge Lang. These Academy members have said that Huntington's work is pseudo-scientific and uses the illusion of science to lend credence to what are merely his own political opinions.

Lang, who is a visiting professor at Harvard this semester, said yesterday: "I'm happy that the NAS has preserved some standards. The questions I have raised concerning the way some political scientists practice their field have received some legitimacy from today's election."

Huntington, who could not be reached for comment yesterday, has maintianed that Lang and his supporters have taken his use of mathematical symbols to mean more than he intended.

Class V

Chairman of the Government Department Robert D. Putnam said yesterday that Huntington was one of the "most distinguished political scientists of this century" and that he was surprised that a body judging scholarly merit would not elect Huntington.

"I think his work is of very high quality and represents good social science," said Putnam, who is not a member of the Academy.

NAS members opposed to Huntington have said that he is but one example of what they fear is a decline in the standards of the Academy's social scientists, who are known as Class V. These members said that what they consider a lack of scientific standards within Class V may be indicative of a general Academy trend.

"If you start with social science, and thenpolitcal science, and now their proposing toinclude agricultural sciences, this academy memberwonders where the hell it will end," said anopponent of Huntington speaking on the conditionof anonymity.

Last month 11 members of Class V responded tothe criticisms of Huntington by circulating aletter supporting the political scientist to allAcademy members. The letter defended Huntington'suse of mathematics as useful and appropriate andtook issue with the tactics of his opponents,which some have said is politically based.

"Mr. Huntington may have been rejected [lastyear] on political grounds. To protect theintegrity Academy this possibility must bedenied," the letter read.

The Huntington debate, which had been carriedon through the mail during the past year, took tothe floor at the NAS meeting yesterday.

There was "a big, big discussion on largeissues" before members voted to block Huntington'selection, several Academy members said. Thesemembers said the defeat was largely due to a fileof documentation challenging Huntington'sscholarship that Lang has been distributing tomembers for more than a year.