A group of D.C. Superior Court judges yesterday failed to persuade the Justice Department to rescind its scheduled cutback in the U.S. Marshals Service here. Seven judges presented their arguments against the Reagan administration's plan to fire more than one-third of the 122 deputy marshals in the District at a meeting with Justice and U.S. Marshals Service officials.

Judge Fred B. Ugast, acting chief judge while H. Carl Moultrie I is recuperating from eye surgery, said after the meeting the judges received "no assurances" that the administration would modify its proposal to fire 43 marshals next month.

Because of the District's continuing ties to the federal government, the U.S. Marshals Service here still performs many functions in the city's D.C. Superior Court, such as ensuring courtroom and witness security, shuttling prisoners in and out of the courthouse, executing warrants, enforcing evictions and serving papers in civil suits.

"We are certain that the District of Columbia criminal justice system cannot effectively function" with the reduction proposed by the Reagan administration, Ugast said.

"The dangers to the citizens of the District of Columbia as well as to those persons visiting our nation's capital is apparent" if the cutback is not rescinded, he added.

"Without the required level of support and funding," he said, "this court cannot function."

Justice Department officials have contended that, even with the proposed reduction from 122 marshals to 79, the deputies will still be able to protect the judges and witnesses and execute arrest warrants. But they no longer will be required to perform other functions that now occupy part of their work day.