Mr Carpenter said lawyers had advised the government to challenge last week’s Federal Court ruling granting the Noongar people native title over more than 6,000 square kilometres of Perth and its surrounding area.
Federal Court judge Marray Wilcox found that the Noongar people had maintained a connection to the area since white settlement began.
Mr Carpenter told ABC television that the ruling represented a radically different interpretation of native title law, which needed to be clarified.
“This isn’t a matter of state government trying to throw out a decision because we think it’s inconvenient or we reject native title. Far from it,” he said.
"The legal advice to us from our team is that Justice Wilcox's decision was so out of line with every other native title decision that goes before it that he has fundamentally changed the law and that needs to be clarified by appeal to the full bench of the
Federal Court," Mr Carpenter said.
"If it was not necessary, I wouldn't appeal it."
Earlier on Thursday about 500 Noongar people rallied outside WA’s state parliament, celebrating the recent native title ruling and urging the state government not to appeal the decision.
The crowd, many holding the Aboriginal flag and red, orange and black balloons matching the flag's colours, booed and chanted "stop the appeal" and "no appeal" when state treasurer Eric Ripper addressed the rally.
The premier said he supported native title in principle, but the law had to be applied consistently and that would form the basis of the appeal.
South West Aboriginal Land and Sea Council (SWALSC) chief executive officer Glen Kelly earlier said the council would be willing to negotiate with the government.
Premier Carpenter said more than 500,000 sq km in WA had been acknowledged under native title and 100 more claims were being processed.
"We have done more to resolve native title issues in Western
Australia than any other state has ever dreamed of doing," he said.
Earlier this week, Mr Carpenter dismissed as ridiculous claims from Federal Attorney-General Philip Ruddock and West Australian Liberal senator Alan Eggleston that the ruling could block non-indigenous people's access to the city's beaches, parklands and waterways.