The FBI has cut back its domestic intelligence activities sharply, especially the use of clandestine informers, in the wake of last year's controversy over illegal surveillance of dissidents during the last decade, the General Accounting Office said yesterday.

But the congressional watchdog agency said said the FBI is still in need of a congressional charter laying out objectives and limits on the techniques it uses in order to prevent an erosion of its new safeguards.

The GAO findings are included in a 95-page report presented to the House Judiciary Subcommittee on Civil and Constitutional Rights. The report is the GAO's second in two years on the FBI.

In his review of eight months of FBI activity last year, the GAO said it found no clear and significant violations of Justice Department guidelines by FBI agents, but uncovered several instances in which personal information of questionable relevance to investigations was included in FBI files.

The GAO credits a new system of intelligence guidelines set up by then Attorney General Edward Levi in 1976 for the sudden drop in FBI abuses and for its smaller caseload.

Of comparable importance, the report notes, is the declining level of political protest from the high points of the late 1960s and early 1970s.

While generally commending the FBI on its efforts to control itself, the report once again raised questions about the worth of domestic spying. Only 10 of the 319 cases it chose at radom to review produced information useful in solving criminal investigations, the report said.

"Despite the improvement in the direction and control of domestic intelligence, there are still few visible results," it said.

" [WORD ILLEGIBLE] Realitically, this may be the best that can be expected, particularly in view of the greater restrictions now placed on the FBI and its past record when there were fewer restrictions and less control."

In a 1973 report, the GAO found that of 797 cases only 10 led to prosecutions and eight to convictions.

In statistical terms, the drop in FBI activity in recent years is astonishing.The number of pending cases dropped from 9.814 on June 30, 1975, to 642 on June 30, 1977.

In 1974, the FBI had 157 organizations and "an undeterminable number" of individuals under investigation; last month, there were 17 organizations and 130 individuals, the GAO said.

The number of agents in domestic intelligence activities dropped from 788 in 1975 to 143 in July; the number of informers tell from 1,100 to 100.

The continued - though limited - use of agents produced some dispute between the principal GAO witness and the subcommittee chairman. Rep Don Edwards (D Calif.)

Noting that of 214 sample cases involving surveillance of individuals only one led to the uncovering of criminal activity. Edwards asked, "Is it appropriate to keep thousands of Americans under survelliance, [involving] everything they do, interviewing their employers, just because two or three people say they're going to stage a demonstration?"

What it really comes down to is whether we should have a surveillance program at all," replied Victor L. Lowe, the GAO's general government division director.

"Personally, I feel more comfortable with the FBI out there looking at some of these people," Lowe said.

Lowe added there is "some likelihood" that the news restrictions on the use of informers have resulted in some underground activities going undiscovered until a crime has been committed.

The report also notes with disfavor that the Justice Department unit created to regulate FBI field investigations is currently not staffed pending the installation of U.S. Judge Frank M. Johnson Jr. as the new FBI director.

"I don't think the director of the FBI should have any vote in choosing the new attorneys for the unit, said Rep. Harold J. Volkmer (D. Mo.). "No way, you don't put the fox out to look, for the chickens."