The Opposition said secondary students would no longer have to complete a research project as part of their South Australian Certificate of Education (SACE) if it won next year's state election.

The Opposition said it planned also to offer senior students a number of entrepreneurial subjects and create three high schools specialising in that area.

Liberal Leader Steven Marshall said the research project would remain available to students, but they could have the option of completing a fifth Year 12 subject instead.

"We don't think it serves the students of South Australia by making it compulsory," he said.

"We've had a huge amount of complaints about it and now we've responded by saying from 2016 the research project will be optional for SACE students."

Mr Marshall said many South Australian students left to pursue apprenticeships before finishing Year 12.

If elected, he said the Opposition would fund apprentices to do school subjects after work hours so they could complete their SACE.

"At the moment you have the option of doing a school-based apprenticeship where you are at school full-time and you go off to do your apprenticeship part-time so you clock up some hours, but it's a pretty slow rate," he said.

"We want to give people the option of leaving school at the end of Year 11, embarking upon their career, starting their apprenticeship and then, most importantly, completing their SACE part-time."