Colin Barnett was named WA's 29th premier more than two weeks after the election was held.

He was sworn in this morning along with his 17-member cabinet, which includes 13 Liberals, three Nationals and Independent Liz Constable.

Mr Barnett said his government's legislative priorities when parliament resumed - probably late next month - were to reintroduce surrogacy laws, protect Royal Perth Hospital, change "truth-in-sentencing" provisions and introduce mandatory sentences for people who assault public officers.

"It's a great honour to have been sworn in," Mr Barnett said.

"I thank the people of Western Australia for the trust they have placed in myself and my colleagues. I'm excited now by the prospect of getting on with the job... and hopefully setting up Western Australia for a very prosperous future," he said.

His Cabinet would start work today, familiarising themselves with their portfolios and "getting on with things they can achieve", Mr Barnett said.

A priority was to establish several funds under the $700 million Royalties for Regions program which was the cornerstone of the Nationals support.

Mr Barnett said he would also meet with Japanese firm Inpex this week, in an effort to persuade the company "by common sense" to locate a processing plant for its Browse Basin project in WA.

The company is expected to announce it will build the plant in Darwin, a decision Mr Barnett said would "add billions" to the project.

However, he blamed the previous Labor government for the situation. Its policy was to have one processing hub in the Kimberley region for all the Browse Basin projects.

Inpex's efforts to build a plant on the environmentally-sensitive Maret Islands have not progressed past the planning approvals process and it entered negotiations with the Northern Territory government.

"It's not in Australia's interests... for that gas to go to Darwin. Browse Basin gas should come ashore in Western Australia. I fear that will not happen.

"I fear (Inpex) have made their decision (but) I'm certainly not giving up on it," Mr Barnett said.

"The time for government action on Inpex was months ago, back in May."