Two conservatives vowing to restore traditional education to Montgomery County were elected to the school board yesterday, tightening the grip of the conservative majority that took control two years ago.

In Prince George's County, two of the three blacks seeking board seats lost; the election was being watched as an indication of black voting strength in the county.

In Montgomery, conservatives Marian L. Greenblatt and Suzanne K. Peyser and liberal incumbent Blair G. Ewing won in the nonpartisan, at-large election. Greenblatt dominated returns with 121,540 votes, followed by Peyser with 111,302 and Ewing with 100,937.

The unsuccessful candidates were Marilyn J. Praisner with 94,869 votes, Michael F. Goodman with 88,580 and Sandra M. King-Shaw with 85,370.

The new board that convenes Dec. 1 will have a 5-to-2 conservative majority, one seat stronger than the current board's.

Greenblatt, an incumbent who is a former teacher and served as board president in 1978-79, has often spoken for the conservative majority that has worked in the last two years to make student attendance requirements more stringent, require written final tests in all major subjects and introduce a pilot program for countywide final exams.

At a noisy celebration at her Silver Spring home last night, Greenblatt said the election was a mandate: "I think people are saying (in this election) that they want to restore traditional education, that they like what the board has been doing and that we should continue our policy in that direction."

Peyser is a part-time high school teacher in the county who took her two daughters out of public schools a year ago and enrolled them in Bethesda's private Holton-Arms School.

Ewing, a federal government employe, waged a bitter campaign against Greenblatt, accusing her of appropriating the back-to-basics label and calling him a "permissive liberal."

In Prince George's County, incumbent Norman (Chuck) Saunders defeated challenger Mary Touchstone, getting 10,555 votes to Touchstone's 7,363. Touchstone was one of three black candidates in the board contests. Saunders, well known for his opposition to busing, remained as popular with the voters in the conservative southern third of the county as in 1973, when he beat another black challenger, Cameron Barron.

Catherine Burch, a housewife who ran a low-budget campaign based, she said, on door-to-door campaigning, defeated a second black candidate, Malinda Miles, 6,423 votes to 4,890. Miles, who ran with the endorsement of the Prince George's County Educators Association and the seat's current holder, Chester Whiting, vowed to continue to be active in education issues. Burch looked forward to "fitting in" on the school board.

"God knows I'll just do my damn best, working with everyone else on the board for the students of Prince George's County. I'm ecstatic," Burch said.

The defeat of Touchstone and Miles means that Bonnie Johns, who ran unopposed, will remain the only black on the school board. Blacks make up 49.9 percent of the county's public school students.

Voters in the Laurel, Calverton and Beltsville area elected incumbent Doris Eugene over teacher and former bricklayer Paul Duncan by 9,849 votes to 6,001. Eugene, a 20-year veteran of PTA involvement, credited her supporters and campaign workers for the victory.

The other unopposed candidates, Jo Ann Bell in the District Heights area and Susan Bieniasz of New Carrolton were also returned to office.