The Tertiary Education Union says a move to shorten the time it takes to earn a master's degree is based on making money rather than good academic reasons.
Tertiary Education Minister Steven Joyce has announced students will be able to complete the qualification within a year to 18 months, instead of two years.
Union president Sandra Grey said the main concern is that the move is primarily aimed at attracting international students.
She said they are an important part of the education system, but should not be seen as a way of grabbing cash and propping up the sector.
But Mr Joyce said it is good to have international students coming into New Zealand and sharing their talents and adding to the education system.
He said shorter degrees are offered successfully overseas.