The Educational Institute of Scotland (EIS) said cuts of £16 million would see some 60 primary posts under threat as a result of a restructuring.
In addition, 20 staff who specialise in teaching pupils with additional support needs such as autism and 10 teachers who deal with pupils whose first language is not English could also go.
The EIS hit out after the council announced the measures last month as part of £70m of budget cuts and savings in the next two years.
The warning comes on the day of the council's budget, where the Labour administration will also unveil a £36m investment in the city's roads and footways over the next two years, £12m more than previously announced.
It comes amid claims by public sector union Unison that vital council services were being hit hardest by budget cuts, and calls for a review of local government funding.
The union said councils have lost 34,500 jobs since 2008/09, with major impacts on services right across the country.
Hugh Donnelly, secretary of the Glasgow EIS Local Association for Glasgow, said: "You can't take £16m out of Glasgow's education budget and not expect an impact on quality." However, a council spokeswoman defended the cuts, saying: "The council's budgets are under intense pressure and the proposals are about protecting priority areas."
The spokeswoman also stressed the removal of additional support teachers were in special schools and would not impact on support in mainstream schools.
l One of Scotland's smallest councils has revealed a funding gap of £4.4m over the next three years, with details of savings and cuts revealed at next week's budget. But although Inverclyde has shown councillors options on how it plans to balance the books it has refused to publicise these until next Thursday's meeting.