Bill McGregor, general secretary of the Headteachers' Association of Scotland, said the clear message was that pound;34 billion should be spent on schools in England.
The money was due to go directly to schools in England from this week, with the amount for a typical primary set to rise from pound;31,000 to pound;44,000 and for a typical secondary from pound;98,000 to pound;150,000 and to Pounds 190,000 next year.
Mr McGregor said: "In Scotland, it doesn't work like that. Our share has to go to the Executive which has to decide how much it will allocate to education, and that then has to go to local authorities who have to decide what they are going to do.
"We will be greatly disappointed if some reasonable funding doesn't finally go to schools. That is what the Chancellor intended in his Budget speech.
If the money is diverted at Executive or, even worse, at local authority level, we will be protesting loudly."
A spokeswoman for the Executive said: "Decisions will be made on how to spend the consequentials in due course."
The executive will have an extra pound;87 millon to allocate but can decide not to spend any of it on education.
Analysis of the Chancellor's announcement shows that the pound;34 billion announced relates to capital spending on buildings and equipment over five years. The increases for the first two years, a total of pound;12.3 billion, had been announced before last week's Budget, and the actual increase in the amount being spent each year is just pound;1.6 billion.
Mr Brown said in his speech that his ambition was to raise state school spending to the level enjoyed in the independent sector. But he has yet to reveal when he expects that to happen. That would take the English state school average of pound;5,000 per pupil to the pound;8,000 average per pupil in independent schools.