D.C. school officials warned the City Council this week that about 200 teachers could lose their jobs, and some courses could be terminated under Mayor Walter E. Washington's proposed $238 million school budget for fiscal year 1979.

School officials reported at a Council hearing that a minimum of $256 million is needed to operate at an optimum level. The $18 million difference would have to be absorbed through cutbacks in the number of employees' and the amount of services, they said.

of the entire budget, 87.9 per cent is earmarked for teachers' salaries, said Schools Superintendent Vincent E. Reed. "If reductions are necessary, we'll have to terminate teachers," he testified.

Reed said instructirs teaching such electives as language and music would be among the first to be terminated. Additional cuts would be made in community programs, and summer school would not be restored, he said.

The school system has already lost 500 teachers since 1973, said Deputy Superintendent Edward Winner. Under the mayor's budget proposal, vacancies cannot be filled, he said. As a result, class sizes will have to increase, and other classes will have to be eliminated, Winner Said.

School officials are seeking an additional $1.9 million for salary increases, $3.5 million for special education, $1.3 million to cover increased utility bills, $2.3 million for the teachers' retirement fund and $8.5 million to restore lost services and add new ones.

In other testimony, school board members asked that the Council remove the cost of administering the teachers' retirement fund from the school budget because the fund is not then under the board's jurisdiction.

Members also assailed the mayor's proposal to subsidize only Metrobus fares, and warned that the costs of maintenance and supplies will exceed what the mayor proposes to provide.

Board member Thermane E. Evans said that if the ouncil approves the mayor's proposed $4.4 million subsidy for bus fares only, "citywide services to children will be seriously undermined."

Arguing for Metrorail subsidies as well, Evans said that "a student who lives in Anacostia and attends the Ellington School for the Arts in Georgetown can end up paying $1.20 a day in public transportation costs."

As for building maintenance, Winner said the mayor's budget provides only $5 million for damage tht twill require $19 million to correct.

Board member Elizabeth C. Kane added that $2.7 million is needed for books and ussupplies over and above the mayor's proposal. If the schools do not get the money, they willl be unable to upgrade curriculum materials, she said.

In a hearing last week, board members heard parents and educators describe how budget cuts are already hindering the education of the city's public school students.

Will Meyers, representating the Alice Deal Home and School Association, said many parent s are concerned over their children's outmoded and tattered textbooks.

Raymond Hannapel, a representative of the Wilson home and School Association, added that the per-pupil allotment for curriculum material had already decreased steadily over the previous seven years.