In the Times/CBS News Poll, 411 blacks were questioned, about four times the usual number of blacks in a nationwide sample. The polling was begun June 23, before Mr. Jackson went to Central America and Cuba. This was also before the most recent controversy developed about his relationship with Louis Farrakhan, the leader of a Black Muslim sect, and Mr. Farrakhan's attacks on the Jewish religion.

The registered Democrats were asked, ''Who would you like to see the Democrats nominate for President in 1984 - Walter Mondale, Jesse Jackson or Gary Hart?''

Among black registered Democrats, 53 percent said they preferred Mr. Mondale, as against 31 percent for Mr. Jackson and 7 percent for Mr. Hart. The rest had no preference.

The poll showed that three-quarters of registered blacks disapproved of the way Mr. Reagan was handling the Presidency and that 82 percent said they would vote for Mr. Mondale and 5 percent for Mr. Reagan if the two men faced each other in November. In 1980, Mr. Reagan won 11 percent of the black vote in the general election and President Carter won 85 percent, according to an Election Day poll by The New York Times and CBS News of voters who had cast their ballots.

Black politicians who have worked in the Presidential campaign this year said they were not surprised by the poll's findings. Many said the strong Jackson vote in the primaries, as John Lewis, the longtime civil rights activist, remarked, was ''symbolic.''

''A great many people wanted to be identified with Jesse Jackson's candidacy as a protest and as a message and as a matter of pride,'' said Mr. Lewis, an Atlanta City Councilman who is a Mondale supporter, ''and a great many wanted him to do well. Now they must play in the real world, and they know that the real fight is between the Democratic party and Reagan.'' 'Response to Reality,' He Says

''The people in your poll were responding to reality,'' said David N. Dinkins, New York's City Clerk, who was Mr. Jackson's campaign coordinator in Manhattan.