National Urban League President Vernon E. Jordan Jr. said yesterday that, instead of making the continued progress they expected at the start of the 1970s, blacks in America lost ground to whites economically over the last 10 years.

A decade ago, according to a report released by the Urban League yesterday on "The State of Black America," black family income averaged about 61 percent that of white families.

By 1978, however, the last year for which such statistics are available, it had dropped to about 59 percent, Census Bureau reports show.

Moreover, the reports said, there are more blacks in poverty today than at the start of the 1970s.

And black unemployment (11.3 percent) is not only more than twice as high as white unemployment (5.1 percent in 1979), but is actually higher than it was in the 1960s and much higher than at the start of the 1970s, when it was only 8.2 percent, the report continued.

"For some, a few," Jordan told a news conference in releasing the report, "it's a little better. But for the vast majority of black people, they're all boat people without boats, cut adrift on an ocean of discrimination, poverty" and other social ills.

Moreover said Jordan in a gloomy presentation, the international situation and "the spirit of Proposition 13" have led to a situation in which the nation's attention and money are being "focused on inflation, energy and defense to the neglect of racial equality, full employment and urban revitalization."

Jordan said "the same people who charged that social problems couldn't be solved by throwing money at them are anxious to try to solve international problems by throwing money at the Pentagon."

The Urban League report was issued a week before President Carter's Budget Message to Congress, in which program levels for all the key antipoverty programs favored by the league will be recommended by the president.

Jordan made clear that the report is intended to escalate pressures on Carter and Congress not to abandon social programs because of defense needs. Jordan, citing President Truman, said national security is as much a matter of domestic-strength as military.

Jordan also said the time has come to put an end to any rift between the U.S. black and Jewish communities over Israel and affirmative action.

"Blacks and Jews have too much in common with one another to remain at odds," he said. He called on Jewish groups, some of which have resisted affirmative action programs for blacks for fear they will lead to quota systems, to accept Supreme Court decisions in the Weber And Bakke cases upholding certain types of affirmative action.

In New York, a spokesman for the American Jewish Congress and Union of American Hebrew Congregations called Jordan's remarks encouraging and quoted Rabbi Alexander Schindler of the UAHC as saying "we must work together to win the war on poverty. . . and make real the promise of full employment."

Although the Urban League's 297-page report detailed progress here and there for blacks, the section which led it off, and which Jordan emprasized, said blacks had made very few economic gains in the 1970s.

Figures cited by Dr. Bernard Anderson, who did the economic analysis for the report, or made available by the Census Bureau, showed that in real purchasing power, measured in terms of constant 1978 dollars, the median family income of blacks in 1970 was $10,544 and rose only to $10,879 in 1978 (3.1 percent). Whites, by contrast, had a $17,189 median in 1970 which rose to $18,368 in 1978 (about 6.8 percent).

In 1969, there were 7,095,000 blacks below the poverty line, and in 1978, the figure was 7,625,000 (a poverty rate of 30.6 percent, according to the Census Bureau). By contrast, the number of whites below the poverty line dropped from 16,659,000 to 16,259,000 between 1970 and 1978. The white poverty rate was 8.7 percent.

Joran said the picture in the 1970s wasn't all dismal -- there was an opening of new job opportunities for some, and new educational opportunities. But for the majority, facing a heavy loss of jobs from the big unemployment crisis of the mid-'70s and a softening of government efforts as a result of the spirit of "benign neglect," he said, "the 1970s were not a time of progress within black America," which suffered "a mood of disappointment, frustration and bitterness at promises made and promises unkept."