The Jimmy Carter blacks worked for in last year's presidential election is not the Jimmy Carter they now find in the White House, the executive director of the National Urban League said yesterday.

So it is with "troubled minds and heavy hearts" that about 8,700 blacks have come to Washington this week to participate in the league's 67th annual meeting said Vernon E. Jordan.

"The sad fact is that the list of what the administration has not done (for blacks and the cities) far exceeds its list of accomplishments," Jordan said in the prepared text of his keynote address at the Washington Hilton. "The sad fact is that the administration is not living up to the first commandment of politics - help those who help you," Jordan said.

Jordan's criticism of President Carter is the sharpest so far by a national black leader, though it has been clear for some time that dissatisfaction has been spreading rapidly among blacks, who were among the President's staunchest supporters.

Carter will have a chance to respond this morning to Jordan's criticisms when he addresses the conference on the topic "National Policy and the Cities."

Partly as a result of Jordan's preliminary strikes last night and yesterday at a noon news conference, many convention participants are eagerly awaiting the President's message.

Jordan said at the news conference that his criticisms should not be viewed as a break between the nation's black leadership and the Carter administration. Blacks in general and the Urban League in particular "are no different from any other groups" - including labor and women - who are dissatisfied with the President's efforts in protecting or advancing their interests, he said.

"My belief is that the president might appreciate this assessment (of his performance on black and urban interests), though he might not like it," Jordan said.

Jordan attacked Carter's welfare-revision proposals, criticized what he called the President's "disastrous proposal to abolish the Electoral College," and questioned the administration's commitment to helping the urban poor.

On the last point, Jordan urged Carter to "symbolize his concern with the urban poor" by going to the sections of New York City that were ravaged by looting and arson during the city's blackout two weeks ago.

A presidential trip to those areas "would be healthy for the President and his administration, which thus far has been disappointing in its sense of priorities and its neglect of domestic reforms," he said.

"We ask tonight that President Carter signal to the nation his concern for the cities and for the poor people who live in them by going to New York, by speaking with the looters and the looted in the South Bronx, Harlem and bedford-Stuyvesant . . . He has to show he understands the anger, the hopes and the needs of the urban poor," Jordan said.

"If the President can go to Clinton, Mass., and Yazoo City, Miss, Miss., he can go to New York," he added, referring to Carter's recent visits to small towns to hold "town meetings."

Jordan said the basic outlines of Carter's welfare proposals "indicate that a real chance is not in sight" in overhauling the welfare system.

The plan has "major conceptual flaws" that include "mandates to keep a ceiling to costs no greater than present welfare-related programs, categorization of the poor, and a work requirement," Jordan said.

The league executive said his organization has a four-step "interim plan that would supplement the present welfare system and ease the plight of poor people while putting in place structures for ultimate reform." The league proposal includes:

A massive job-creation program involving more federal public service jobs and federal and to private industry - "incentives" - to create jobs in high unemployment areas.

An expansion of the food-stamp program, with an emphasis on climinating the requirement that eligible persons put up a certain amount of cash to receive stamps.

"Extending and improving programs [such as unemployment and Social Security] that cushion the effects of unemployment and economics losses due to health problems."

A refundable tax credit, "using the tax system to provide modified income assistance" to persons now on welfare rolls.

As a "signal" that the President understands the needs of blacks and poor people, Jordan urged him to adopt the league's welfare revision proposals and to abandon plans to abolish the Electoral College.

Speaking of the administration's "electoral reform" proposals. Jordan said: "It is unseemly for an administration that owes its existence to solid black electoral support to propose a system whose effect would be to sabolege, and in 1980 the black vote will voting power.

"Do away with the Electoral College, and in 190 the black vote will not make the difference it did in 1976," Jordan said.

He said he does not question Carter's commitment to equal opportunity, despite what he views as the shortcomings of Carter's presidential performance in that area.

"But we are learning that even an administration sympathetic to our needs and in harmony with our aspirations needs sustained pressure, and we are here in Washington to apply some of that pressure," he said.

In August, he and other national black civil rights leaders will convene a private strategy meeting to discuss ways of continuing to pressure the administration," Jordan said.