Maryland's judges, seeking a way to reduce discrepancies in sentences imposed for similar crimes, voted yesterday to introduce standard sentencing guidelines in all Circuit Courts across the state. Persons with no prior criminal records will tend to get lower sentences under the guidelines, while those with major records will tend to get heavier sentences.

Beginning July 1, Circuit Court judges will be given manuals to refer to when imposing sentences, will file reports to a central office on each case, and must report in writing their reasons for deviating from official sentencing guidelines.

The near-unanimous voice vote of about 200 judges, taken on the first day of their annual conference in Bethesda, constitutes an expansion of a pilot project begun in 1981 in Prince George's, Montgomery and Harford Counties, and Baltimore City.

Maryland judges began the project partly in recognition of the great authority they have in sentencing, particularly when compared to judges in other states. In Maryland, a judge's sentence cannot be appealed except in cases involving the death penalty.

According to data collected by 10 judges heading the pilot effort, sentences given to criminals with no prior records before the project began averaged 29 months, compared to an average 18 months for those sentenced during the project. Criminals with major records received an average of 52 months in jail before the guidelines were introduced. Afterward, they received an average sentence of 88 months.

The crimes covered by the guidelines include offenses against persons, and those involving drugs, weapons and property. Exempt are arson, first-degree murder, District Court appeals, offenses that carry no jail terms and those for which mandatory sentences have been established by law.

Judges using the guidelines are required to fill out "work sheets" before sentencing, scoring the defendant on such things as previous record, use of weapons and victim injury. They then refer to charts listing recommended sentence ranges for criminals having the same total scores.

The new guidelines have received little opposition from either prosecutors or defense attorneys. "At first I was opposed to them ," Prince George's State's Attorney Arthur A. Marshall Jr. said yesterday. "But generally speaking, the number of years involved are reasonably fair."

Circuit Judge Perry G. Bowen Jr. of Calvert County told judges at yesterday's conference that the guidelines will be especially useful for new judges. "Nobody comes to the bench with any experience in sentencing human beings," he said.

Much of the discussion before the vote centered around plea bargaining, where sentences are often worked out before the case is brought into the courtroom.

District Judge Irving H. Fisher of Prince George's County said that including plea bargaining in the guidelines was "a charade" and "a big waste of time."

Circuit Judge Howard S. Chasanow, also of Prince George's and vice chairman of the guidelines board, acknowledged that some plea bargains resulted in lower sentences because they were the only means of reaching a conviction. But the result, he said, should still "represent a fair and rational sentence."

The board's chairman, Circuit Judge Marshall A. Levin of Baltimore City, told the judges that between 85 and 95 percent of all sentences are the result of plea bargains, "so obviously you cannot leave plea bargaining out."

Prince George's Circuit Judge David Gray Ross, one of the few judges who voted against the sentencing guidelines and a former state legislator, said afterward that the guidelines procedure is "an invasion of the legislative process."

He expressed concern that "the next step will be to remove sentencing from the judge." Ross, who tries most of his cases in juvenile court, said he has usually not adhered to the guidelines while sitting on an adult court bench.

Levin, however, said the introduction of self-imposed guidelines was partly a way of avoiding legislative action. "If the judges don't straighten their own sentencing house out, the legislature is going to do it for them," he said.