Charging that the Reagan administration is not willing to enforce the nation's civil rights laws, black leaders at the annual convention of the NAACP today began to outline plans for nationwide black boycotts against companies and industries that do not offer equal opportunities to blacks.

"We have made a decision at the national level to move more aggressively and more frequently to use boycotts," said Thomas I. Atkins, general counsel for the NAACP. "We serve notice to those against whom we may use boycotts ."

Atkins said the decision to move forward on boycotts was made because of the sagging economy and "the resurgence of racism on the part of employers and business people. This economy has tightened up, and, as a result, people have taken that as a license to engage in racially restrictive practices that they might have been afraid to engage in some years ago.

"There's a belief that the federal government under this administration will not enforce the civil rights laws. The federal government may not, but the NAACP damned well will," he said. "Ronald Reagan cannot buy protection for the bigots in this country."

The issue of boycotts is a touchy one for the NAACP. The Supreme Court is expected to rule this week on a lawsuit against the NAACP that dates back to its 1966 boycott against a group of white merchants in Port Gibson, Miss.

Picket lines were set up there to protest the fact that there were no black elected officials although blacks made up a majority of the population of the town and surrounding county.

The state courts ruled that the boycott was illegal because the merchants were not directly responsible for blacks' not being elected. The lower state court imposed a fine of $1.25 million against the NAACP and individual defendants, but the fine was lifted later by the state supreme court.

The NAACP is seeking to go beyond that to have the Supreme Court declare the Port Gibson boycott legal. But, Atkins said, even if the court rules against the NAACP, "I guarantee you, it would not mean we would not boycott."

Workshops were held all day today for the 10,000 delegates and supporters to set up guidelines for boycotts that could be conducted within current law even if the suit is lost.

Atkins and other officials would not say whether specific firms have been targeted, but the NAACP has been working for some time on a study of the film industry, where black actors and actresses say they are finding it almost impossible to get work. Several delegates from the Hollywood NAACP branch have said they expect a boycott against films produced by many of the major movie studios.

Curtis E. Rodgers, assistant general counsel of the NAACP, noted that black spending power in 1981 was $140 billion, as he outlined "Operation Fair Share," the NAACP's project to focus black patronage and spending on firms that share the goals of black Americans.

Rodgers said the priorities of Fair Share include increased access for blacks in entry-level jobs, increased appointments of blacks to senior management positions and corporate boards of directors, more involvement of companies in doing business with or buying supplies from minority firms and enactment of "set-aside programs" to guarantee a certain share of a company's contracts to minority firms.

He added that of the 15,000 directors on the boards of the Fortune 1,000 largest American corporations fewer than 100 are black.

Earl C. Graves, editor and publisher of Black Enterprise magazine, warned the delegates that in the current political atmosphere, "We must learn to be more dependent on ourselves, economically and politically.

"We know by now that as black Americans we cannot depend solely on government. We cannot depend on anyone or anything outside ourselves to provide real economic opportunity and justice.

"When we look back to those days . . . when we moved the heart and soul of this nation in our quest to achieve civil rights, and when we look at the way things are today, we realize that we have been standing in the same station waiting for economic opportunity, watching train after train pass us by," he said.

"We have been waiting for the next budget . . . the next election . . . . We have been waiting and waiting in the station at the end of the economic line for too many generations. We are here today because . . . we realize that we are going to have to move the train of equal opportunity out of here ourselves."