Vice president Mondale said yesterday that the Carter administration's commitment to civil rights is strong, even as a leading civil rights group was describing the Carter performance on civil rights last year as "mixed."

That assessment of the administration's fiscal-year record in the field came from the Leadership Conference on Civil Rights, at whole annual meeting Mondale was the featured speaker.

Saying that civil rights progress is more difficult now than in the past, Mondale called for ". . . a new constituency of conscience in America . . ." around economic justice and human rights.

He said the civil rights reorganization President Carter plans to propose next month will put "new teeth" into the Equal Employment Opportunity Commission, strengthen the Office of Federal Contract Compliance, and give "new power" to attempts to ban age and sex discrimination.

The leadership conference, meanwhile, said in its report on Carter's first year: "The anti-civil rights pronouncements and posture of the previous two administrations have ceased . . . But President Carter has made little use of the moral influence of his office to further public understanding of continuing denials of opportunity and to rally public support for effective civil rights enforcement.

The leadership conference is a 28-year-old coalition of 140 labor, religious, civic, civil rights and other groups that monitor civil rights issues.

Its 37-page report blamed ". . . the rhetoric of the last two administration [those of Ford and Nixon] . . ." for helping convince ". . . much of the American public that discrimination was a thing of the past . . ."

Under Carter, the report said, "enforcement in some areas has improved, but progress has been slow and in some cases nonexistent. Many of the important battles are still to come."

It praised Carter for his July memo ordering strict enforcement of the law banning discrimination in federally funded programs.

It criticized him for failing to name a senior civil rights adviser, and for not setting up a civil rights unit in the Office of Management and Budget to improve the management of federal civil rights programs.

Those programs have been criticized repeatedly in the past by the U.S. Civil Rights Commission and by the General Accounting Office, as well as by civil rights groups.

The report also noted wryly that the Justice Department ". . . still goes to court to defend agencies with sorry records of enforcement."

Mondale was interrupted several times by applause as he told the group that the one wish he and Carter have "above all others" is "to work with you to fulfill our nation's historic commitment to the promise of equal rights."

He promised strict enforcement of civil rights laws, strong support of affirmative action "as a legitimate and effective tool" new sensitivity "throughout government to the special needs of minority citizens, and women, and the disabled," and a continuing commitment ". . . most of all, to jobs."

And he called for help in creating ". . . the most effective instruments for the protection of equal rights this nation has ever seen."

Mondale said Americans should never doubt the civil rights gains that have been made.

"But the fact remains," he said, "that a black child . . has about one-half the chance of completing college as a white child . . . two and one half times the chance of becoming unemployed, a life expectancy which is six years less, and the prospects of earning only about half as much."

The figures for Hispanic Americans and other minorities ". . . are just as bad, and sometimes worse," Mondale said. ". . . Gandhi once said that if God ever came to India he'd better come in the form of bread. If God comes to the ghettos of America, he'd better come in the form of jobs."

The leadership conference report had kind words for a number of Carter administration activities, including:

The reorganization of the EEOC in an attempt to eliminate a backlog of 130,000 discrimination complaints, and a switch in emphasis from handling individual complaints to taking on large employers.

Regulations issued last summer by the Department of Health, Education and Welfare to protect the handicapped from discrimination.

New HEW guidelines intended to eliminate discrimination in colleges and universities.

The Justice Department's stand in favor of affirmative action in the Bakke case.

The report criticized, among other things:

Civil Service Commission procedures that "still load the dice against federal workers who have been victims of discrimination."

Lack of an "adequate" housing subsidy program for low-income families.

Action "in only a few cases" to make sure suburban housing is open to minorities.

A "poor" civil rights record in the health and social service fields, including lax or nonexistent enforcement of anti-discrimination laws, and inadequate compliance staff.

"Sluggish" protection of the rights of minority veterans to equal treatment in benefit programs.