U. S. District Court Judge Oren R. Lewis cajoled, teased and interrogated federal prosecutors and attorneys for Fairfax County yesterday during a preliminary hearing in the Justice Department's antidiscrimination suit against the county.

"You're scared of [the] Justice [Department]," Lewis told Assistant Fairfax County Attorney Jack L. Gould. Gould responed by shaking his head to indicate he wasn't.

The judge said that when he was a lawyer, he had "tried hundreds of lawsuits and I never worried about the other side's evidence. I worried about my own. If I didn't have the evidence, you know what my philosophy was? I'd make the best settlement I could [so] we could get out of there with our shirt on."

Later, Lewis turned to James S. Angus, the senior Justice Department trial lawyer, and accused him of "shifting the burden of proof from the accuser [the Justice Department] to the accusee. . . . There's too much antipathy in this case. . . . We've go to get on with it."

At issue is whether or not the county is guilty of discriminatory hiring practices against blacks and women. The government argues that the county does disriminate and has asked that more than $7 million in federal revenue sharing and other aid be shut off.

Yesterday's hearing dealt with standards to be used in measuring the county's hiring practices.

At one point, Lewis suggested a course of legal action fro the county, telling Gould, "you've got to make [this] defense. If I were you. I'd forget their [standards]. I'd say I [meaning the county] don't intend to be an employment center for the District of Columbia. Here's how we get our employes. You could say that and sit down."

When Gould protested, Lewis called the county's personnel classification system "bureaucratic jargon," adding that "I don't see any reason why this should be drawn into a great mountain."

At the end of the hearing, Lewis denied the county's request that he rule immediately on hiring and promotion standards by which the county should be measured.

"The Justice Department... would stretch the norm [of blacks available for employment] as far as they can. . . . They would get a higher percentage of blacks [available for work] if they include Baltimore... or Philadelphia, or New York and Harlem," Lewis told Gould in advising him that the subject could be properly brought up at the trial.

"I have a grandson who was born and raised in Virginia, and lives in Virginia, and he works in Rockville. . . . He goes where he finds the job." Lewis said.

Lewis did grant an oral request, made at the end of the hearing, that the Justice Department inform the county by Monday of what standards it had used in bringing the suit.

Lewis practiced law in northern Virginia for 21 years before his appointment to the bench 19 years ago. Although he is considered to be in semiretirement, he regularly hears cases in federal court.

A trial date in the Fairfax County Antidiscri,ination case is expected to be set at a preliminary hearing Thursday. At that time, a trial judge will also be chosen, Lewis said yesterday.