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Two thirds of young same-sex couples in Australia want to tie the knot, a new study has revealed.

Out of the 2,232 people polled in the University of Queensland online survey Not So Private Lives more than 65 per cent of homosexuals aged under 20 and 62 per cent under 30 preferred marriage for their long term relationships.

The survey also revealed a growing confusion about anti-gay marriage laws.

"Particularly young people right now think 'What's the big deal? I'm accepted, why can't I get married like my friends?' it just doesn't make any sense anymore to a younger generation who are seeing acceptance," UQ School of Psychology researcher Sharon Dane said.

The research is the first work to consult same-sex couples on their preferences regarding relationships and has been submitted to the federal Senate inquiry into the Marriage Equality Amendment Bill 2009.

The bill aims to change the Marriage Act to allow legal same-sex unions and recognise same-sex married couples from overseas.

"This just completes the picture, it shows the gay community also have this is very much at their forefront and the issue is not going to go away," Ms Dane said.

"It [marriage] is important to society, it is universally understood. It takes no explanation, if you say `I'm married to that person' everyone across the world, irrespective of religion or race, understands what that means.   

"It in turn normalises same-sex relationships and they are not seen as being different."

Ms Dane said the views of gay couples in Australia towards marriage reflected the growing wave of international opinion moving towards legal same-sex marriage.

Seven  countries around the world now allow same-sex marriage including the Netherlands, Sweden and Canada. Same-sex marriages are performed in some parts of the United States but their legal status remains in flux.

In Australia, marriage is defined under the Marriage Act to be specifically a union between a man and a woman and excludes all unions entered into overseas between same-sex partners.

The Bureau of Statistics recently released data showing registered marriages were at a 20-year high -  with civil celebrants, not religious officials - performing 65 per cent of marriages.

The movement of marriage away from religion meant there was increasingly little reason to prevent same-sex couples from tying the knot, Ms Dane said.

"People from any religious background, people who are atheists, can get married in Australia. It is not a criteria that you need to be a religious person or of a religious denomination be married and yet that is used as an argument, that it is a religious institution," she said.