"Value-added" exam results could be used to to favour pupils from disadvantaged families and poorly performing schools in the allocation of university places.
Mike Nicholson, director of admissions at Oxford university, said that Ucas, the universities admissions service, was investigating ways of using schools' academic performance as part of pupils' applications.
The proposals, if adopted, could give pupils from lower-ranked schools a better chance of winning a university place than those from high-performing schools.
"Not only is the issue of family data being talked about, but also school performance data. Ucas has been looking at contextual data," Mr Nicholson told delegates at the annual conference of the Independent Schools Council.
He is part of a committee drawing up the plans and said a final announcement was expected within the next six months.
Some leading universities, including Oxford and Cambridge, already use some school data when making decisions on admissions. The new proposals would extend the system to all institutions.
Independent school leaders criticised the proposals, saying their pupils would be unfairly penalised.
Pat Langham, president of the Girls' Schools Association, said: "A good school is going to be penalised. Universities will look at a child who has had really good teaching and they will make a lower offer to a child who hasn't."
The announcement comes days after it emerged that pupils may also have to tell universities if their parents went to university and if they hold professional jobs.
Speaking at the same conference, Boris Johnson, the Conservatives'
spokesman on higher education, said that school league tables should be changed to put more weight on traditional academic subjects.
"We could change the weighting so that a school's achievement in the 'crunchy' subjects was reflected in the league tables. That would be an immediate reform we could institute. We are seeing a diversion of children away from the crunchier subjects in the state sector and they are being ghettoised in the independent sector," he said.