President Reagan's chief spokesman said yesterday that television and news reports have denigrated presidents for the last two decades, and he associated this kind of reporting with the fact that no president since Dwight D. Eisenhower has served two full terms.

"My question to you is, can the modern presidency survive the modern media?" deputy White House press secretary Larry Speakes told the National Association of Government Communicators at the Capital Yacht Club. "Can any man in public office stand up to the daily drumbeat of morning newspapers and the flashing symbols of evening news television shows?

"The steady denigration of the president has gone on for two decades. It has been directed not only at the president but at his use of presidential powers . . . ," Speakes said. He was given an award by the group for "outstanding performance at a time of grave national crisis."

Speakes criticized the White House press corps earlier this week for its handling of the president's comment that it is hard to "justify" the federal government's tax on corporate income. White House aides said the way the story was reported added to the public perception of Reagan as a president who helps the rich at the expense of middle-income and poor people.

The day after these news articles appeared, Speakes told reporters that they gave greater significance to an off-the-cuff remark than they should have, and said that they were "jumping up and down, licking their chops, clapping their hands and doing back flips" over Reagan's remark.

Yesterday, Speakes said that he is beginning to feel that, for reporters, "good news is no news."

He cited constant TV and newspaper reports early in the Reagan administration indicating that inflation was the nation's No. 1 problem. But when Reagan cut inflation from 13 percent to 3 percent, Speakes said, the media didn't send the message that the administration had helped to resolve the No. 1 problem.

Speakes also questioned public opinion polls that show unemployment as the current No. 1 problem.

"And why not?" said Speakes. "Every night we have seen the unemployed line up and march across the television screen, and I certainly would not be one to make light of the people who are unemployed. . . . But why is it that 10.8 percent unemployment is news but 89.2 percent of Americans who are employed and enjoy the highest standard of living are not?"

Calling it a chicken-and-egg situation between the media and public opinion, Speakes said, "Does the public perception that things are bad come first or does the public say things are bad after they've seen the bad news night after night?"

Speakes suggested a "good-news segment" on television news programs. He said he would call the new reporting beat the "upbeat."