Loans of up to ?3,400 are made available to students under the Postgraduate Student Allowances Scheme, and it will now also cover 100 places at the Open University.
The announcement comes amid fears of a postgraduate funding crisis in England, where students do not receive any state support and often have to rely on commercial loans.
Michael Russell, the Scottish education secretary, said: “As part of our work on post 16 education reform we have been looking at ways in which we can simplify and improve student support, including how we fund those studying for postgraduate qualifications.
“We have had a number of very positive discussions around future provision, and are now pleased to say that almost twice as many postgraduate students will be eligible for support from 2012-13.”
In 2009–10, there were 53,925 postgraduates studying in Scotland, according to the Higher Education Statistics Agency.
Robin Parker, president of NUS Scotland, said: “These changes will see greater numbers of postgraduate students get financial support to study.
“With postgraduate qualifications becoming increasingly important, this is clearly a step forward and will hopefully open up opportunities to people from poorer backgrounds that wouldn't have been available before.
“We would have preferred these changes for postgraduates to have come alongside the wider changes planned to simplify the student support system for next year and we would have also preferred a formal consultation process to make sure we get this right.
“However, getting support to greater numbers of postgraduates is good news and will make sure the highest level opportunities are open to students from all backgrounds, opening up huge opportunities for our economy too.”