Ann Kahn, the three-time chairman of the Fairfax County School Board, is expected to be named president of The National Congress of Parents and Teachers (PTA) at the group's 1985 convention in Washington Monday.

Kahn, 58, who left the Fairfax board a year ago to devote more time to her job as the group's first vice president, is the only nominee for election as president, a volunteer job.

"It's going to be two years of very hard work," said Kahn, "but I feel it is a debt I owe this country."

The daughter of Polish immigrants who settled in Denver, Kahn said she has benefited from the American public school system, as has her family, and by serving in the PTA she will repay the country.

Kahn's daughter, for example, is now an assistant commonwealth's attorney in York County and her son is a recent recipient of a doctorate in biochemistry, with an interest in brain research.

"To have achieved these opportunities through the public school system -- I just feel a deep sense of wanting to see the system survive for other children," Kahn said.

She will work out of the PTA's Washington office and spend much of the year traveling to school groups around the country.

Kahn graduated from George Washington University in 1949 with a bachelor's degree in public speaking. She worked on the executive staff of the National League of Women Voters from 1949 to 1955, then took time off to rear her children.

Kahn said that her children initially triggered her interest in the PTA, she said, and she served for one year as PTA president of the former Masonville Elementary School in Annandale.

In the 1970s, she also worked as a registered lobbyist for the National PTA.

Kahn was first named to the Fairfax County School Board in 1973, and in 1980 she was unanimously elected chairman.

During her three terms as chairman, she supported the expansion of school sex education classes and helped create programs for gifted and talented students.

In July 1984, she decided not to seek reappointment to a seventh School Board term so she could devote more time to her two-year tenure as first vice president of the National PTA.

"I realized the presidency was in the offing," she said, "and I knew I could not do both of those jobs and do them well."

As the nation's new volunteer PTA president, Kahn hopes to continue PTA efforts to prevent drug and alcohol abuse, to reduce television violence, and to promote the mandatory use of safety belts and child restraints in all states.

She is also interested, among other things, in the development of programs to safeguard the nation's more than five million latchkey children, age 5-13, who spend part of each day alone at home, waiting for parents to return from work.

Additionally, Kahn said she will continue to oppose tuition tax credits for nonpublic schools, which educate 10 percent of the nation's students. "The money is simply channeled into funds where no public officials can be held accountable," she said.