Justice Department officials, in one of the first concrete responses to the new balanced-budget law, have frozen funding for juvenile justice programs ranging from drug treatment clinics to aid for runaways.

The department's Office of Juvenile Justice and Delinquency Prevention, headed by Alfred S. Regnery, has notified local governments, universities and nonprofit groups that most of its $70 million budget for fiscal 1986 is being put on ice pending a formal request to Congress to rescind the money.

Department spokesman Patrick S. Korten said there has been no formal announcement of a freeze and that only grants awaiting final approval are affected. But he said this involves the bulk of the juvenile justice budget.

Justice officials, like those at other agencies, have been studying how to cope with the Gramm-Rudman-Hollings law, which requires a balanced federal budget by 1991 and mandates the first round of cutbacks for March 1. Since the department's law-enforcement functions are considered sacrosanct, most of the cuts are expected to fall on grant programs.

"There's going to be a whole lot of pulling up short while we wait to see what Gramm-Rudman requires," Korten said. He said the department is still negotiating over proposed cuts with the Office of Management and Budget.

Another department official, Katie Boyle, said that an additional $70 million in criminal justice grants to state and local governments is "under review."

Sen. Arlen Specter (R-Pa.), chairman of the Senate Judiciary subcommittee on juvenile justice, said he has been "deluged by calls" from angry grant recipients. He called the move "a slap in the face to Congress, which repeatedly has rejected every single attempt by the administration to limit or eliminate the funding" for the juvenile justice office.

Specter, who voted for the Gramm-Rudman-Hollings bill, said that Regnery's office has refused to spend part of the money already appropriated for the 11-year-old program.

Don Mathis, cochairman of the Ad Hoc Coalition for Juvenile Justice, which represents such groups as the YMCA, Girl Scouts and Children's Defense Fund, said Regnery announced plans to seek a recision at a public meeting Tuesday. Mathis said that "this is the beginning of dissolving the federal involvement in juvenile justice."

"We're talking about layoffs of people immediately," he said. "We're talking about immediate impoundment of funds. The Justice Department can't even wait until March 1, when Gramm-Rudman takes effect."

Prof. Marvin Wolfgang of the University of Pennsylvania said that his behavioral study of thousands of boys has been funded for years by Regnery's office. He said he was awaiting a pro forma approval for a $500,000 follow-up grant, to begin Jan. 1, when Justice officials called to say the money was frozen.

"It's devastating," Wolfgang said. "My entire staff, my research assistants, my computer programmers, are dependent on that grant."

"No matter what you do, you're going to disrupt someone," Korten said of the budget crunch. Where contracts have been signed, he said, "That money is obligated, period, and will not be taken back."

Korten said it is not surprising to hear complaints from "outside constituency groups who have a vested interest in this money."