Who would have bet six months ago that the public in Prince George's County would overwhelmingly oppose, and the school board would kill, a proposal that would allow some 11,000 more children to walk to a neighborhood school rather than take a bus to a school miles away?

One person in 20, perhaps.

That is precisely what is taking place, however, in this suburban Maryland county of 700,000 that reluctantly but peacefully began massive busing for desegration five years ago.

After listening to predominantly negative testimony at several public hearings over the last two weeks, the county board of education tonight will vote on a motion to indefinitely put aside two reduced-busing proposals. The motion has a good chance of passing. If it fails tonight, it is expected to pass next week after the last of the six scheduled hearing is held.

Some of the nine board members will vote to table the proposals because they did not like the plans in the first place. Others will do so because of the one-sided public sentiment. The result will be the same - the reduced-busing concept will be dead, at least for the next year.

The imminent death of the proposals became obvious last week when board member Sue V. Mills - a longtime busing opponent who was instrumental in pushing the measures at the outset - announced that she was withdrawing her support.

"The message has come through loud and strong," said Mills, "that Prince George's is not ready for this plan of action."

Mills said she was "bewildered" by the lack of public support for the proposals, known as demographic study alternatives. She said there must be a "silent majority" somewhere out in the country that liked them, but that group, befitting its name, was not speaking out.

Whether that "silent majority" exists on this controversial issue may never be known. What is known is that several hundred people - of all races, incomes and communities within the county - have spoken out against the proposals. The message was so clear that another board member who originally supported the reduced-busing concept - Chester Whiting - stopped listening by the fourth public hearing.

"It's dead," said Whiting. "It's obvious. How much do we have to hear?"

By the time that fourth hearing, held this week in Oxon Hill, many of the board members were talking privately about the task forces they would set up to study school closings after the proposals are killed. The reduced-busing proposals included the closing of 11 schools next fall. With the defeat of the proposals, the school closings will have to be handled separately.

Many board members believe that the inclusion of the 11 school closings in the reduced-busing proposals was the fatal mistake.

"We didn't take first things first," said Jo Ann Bell.

"We should have decided what schools will be operating before we tackled the busing plans. And we should have allowed the proper citizen input like we did last year."

Before the board closed 10 schools for the 1977-78 school years, it set up task forces in the communities affected by the closings. This year, the task force concept was abandoned in the rush to push the ill-fated reduced-busing plans.

Bell's theory was supported by a majority of the county residents who opposed the demographic alternatives. At every public hearing, most of those who spoke out against the plans did so because their children attended one of the schools earmarked for closing.

At the Oxon Hill hearing, for example, a group of Upper Marlboro residents spoke against the proposals because they would force their children to shift from a relatively new school, Marlton, to an old and delapidated one, Douglass. Said Thomas Clagett of Douglass school: "If the same conditions existed in the county jail, the state would not allow us to house prisoners there."

Other speakers protested the closingsof Camp Springs and Panorama elementary schools for similar reasons. And at the earlier hearings in the central and northern regions of the county, dozens of residents complained about the scheduled, and what they felt were unnecessary, closing of other schools.

"We really don't know whether the public supports the concept of reduced busing or not," said one board member. "All we know is that a lot of people don't like the closing of their schools in what they think is an arbitrary way."

In the midst of the one-sided testimony this week, the board members were distracted by an internal dispute involving the actions of chairman Norman Saunders, a south county resident who sends his own children to private schools. Saunders wrote a letter on school board stationery that was distributed to all elementary school principals and then sent home via the students to the parents.

Several board members said the letter was decidedly partial - in support of the proposals - and that it made a mockery of the supposedly impartial stance the board was to take during the public hearings. Two sentences in the letter stood out. One sentence read: "I believe that because of . . . changes, much of the busing that began in 1973 may no longer be necessary." Another read: . . . "this time we must hear from those who support the changes . . . "

Board member Bonnie Johns drew loud applause from the Oxon Hill audience when she said the letter "was not in the best interest" of the board or the community. Bell said the letter "makes the hearings very unfair."

Saunders aruged that his letter was simply an attempt to remind the community that the public hearings were taking place. "There is no opinion in the letter," said Saunders, "just fact."

When asked whether a sentence that begins with "I believe" did not constitute an opinion. Saunders replied testily: "I don't have to answer that. You'll draw your own conclusions anyway."