Mayor Marion Barry yesterday vetoed 10 changes made by the D.C. City Council in its recent deliberations on the city budget for the 1981 fiscal year. If the council upholds the mayor's vetoes, it would add $601,000 to the version of the budget adopted by the council.

More than half the disputed items, totaling $342,000, involve cuts made by the council in the mayor's office and in related administrative offices. The reduction voted by the council would have reduced the number of employes in those offices by 11, including three from the mayor's office itself.

"The three positions" Barry said in a letter to the council, "are absolutely essential . . ."

Barry noted that the vetoes were minimal and "demonstrate . . . willingness to compromise" in adopting the budget, which totals just above $1.5 billion.

The city's Home Rule Charter requires the mayor to submit the proposed annual budget to the council, which may take changes and, after its adoption, must return it to the mayor. The mayor is permitted to veto individual changes in the budget, and the council may vote to sustain or override each of these. A two-thirds majority is required to override a veto. The council will meet on the matter Wednesday.

The budget ultimately must be approved by Congress.