A Prince George's County judge has given suspended jail sentences and fines totaling hundreds of dollars to two parents whose children have been chronically absent from school.

It was the first time in the county that a judge has handed down jail sentences -- even though he then suspended those sentences -- for parents in a truancy case. Circuit Court Judge Robert H. Mason suspended the imprisonment provided that the parents, who are unemployed, seek work and see that their children start attending school.

One parent, Shirley Prather, a 52-year-old Suitland resident, was fined $500 on Monday, ordered to perform 50 hours of community service and placed on two years' probation in lieu of a 50-day jail sentence for failing to ensure that her 14- and 15-year-old daughters attended Francis Scott Key Middle School in District Heights. As of mid-February, officials said, the 14-year-old had missed 82 days of school and the 15-year-old 79 days.

Also on Monday, Mason fined Jeannette Lyons, 40, of Clinton $750, ordered her to perform 76 hours of community service and placed her on five years' probation instead of a 75-day jail sentence. Her 10-year-old daughter was absent from Randall Elementary in Clinton continuously from Oct. 8 to April 28, according to the prosecutor, Assistant State's Attorney Jeffrey Harding. Lyons' 12-year-old daughter was absent regularly from Stephen Decatur Middle School in Clinton from Sept. 11 through April 25, according to Harding.

Mason ordered the parents to do their community service at their children's schools.

Both mothers were described by their attorney, Jeff Singman, as living on public assistance. They were convicted of failing to ensure that their children obeyed Maryland's compulsory attendance laws, in two separate jury trials in juvenile court in June.

Those trials were the first time in the state that juries had been used in juvenile court, according to state court officials. The children did not face any charges.

Singman said yesterday both clients wanted their children to attend school, but were not able to force them to do so.

"They were guilty, perhaps, of being bad parents, but they were not guilty of wanting their kids to stay home," Singman said. "They are the kind of parent that is ineffective . . . and they don't know how to enforce discipline. They just don't know how to deal with troubled children.

"The cases could have been handled by removing the kids from the home," he said. "It would have more sense."

Harding said yesterday that the state decided to take the parents to court under a year-old state law allowing such prosecution because they had not responded to repeated efforts by the county school system to make sure that their children attended school. "People will see that we are not fooling around any more," he said.

Prince George's County has the second highest truancy rate in the state, after Baltimore, according to the state education department. On any given day in 1983-84 -- the last school year for which figures are available -- about 9.1 percent, or 9,464, of the school system's 104,000 students were not in school. At least 2,000 of those students are believed to be chronically absent.

Statewide, 8.4 percent of students were absent in that same school year, according to a report prepared for the state.

Prince George's School Superintendent John A. Murphy said yesterday that the "severe sentences" will help convince parents of the importance of complying with state laws requiring school attendance.

"In the past, parents couldn't have cared less -- there wasn't a deterrent," he said. "Now, parents will see there is a pretty strong price to pay."