Teamsters union President Jackie Presser said yesterday that President Reagan will not fire National Labor Relations Board Chairman Donald L. Dotson, "but I presume that they would give him a demotion."

Presser had pushed strongly for Dotson's dismissal and hinted publicly last month that the Teamsters might not endorse Reagan if he refused to go along with the demand.

Reagan refused, however, saying "no deal" would be made with the Teamsters, and the 1.9 million-member union endorsed the president last Thursday anyway.

Presser was asked in a Cable News Network interview yesterday whether he expects Dotson to be fired next year if Reagan wins reelection.

"I know that the president doesn't intend to remove him entirely," Presser replied. "I would presume that they would give him a demotion or bring somebody else in as the chairman that's more qualified than Mr. Dotson."

A White House spokesman declined to say whether the president would replace Dotson as chairman of the NLRB but allow him to remain as a member of the board.

"I have nothing further to add than what the president has already said," spokesman C. Anson Franklin said.

The Teamsters say the NLRB under Dotson has been tilted heavily against labor, and since the board negotiates in disputes between management and labor, the union has lobbied vigorously for Dotson's removal. "I would be really surprised if he remains because of the problem that is existing over there," Presser said.

But he said Reagan has made no promises on the matter. "I haven't had any indication of what was going to happen to him since the day I started to object to him," he said.

Meanwhile, Democratic presidential nominee Walter F. Mondale received a "courtesy" briefing from Reagan's top national security aide in North Oaks, Minn. Mondale, who flies to New York on Sunday to begin his fall travels, spent more than two hours at the briefing by Robert C. McFarlane.