More than 25 per cent of all construction in Australia is occurring in WA, where almost $90 billion worth of projects are currently underway.

A report by Deloitte Access Economics released today said one third of projects committed to or under consideration in Australia were in WA, valued at $140.1 billion.

Including potential developments, WA has $267.2 billion worth of projects in the pipeline, the investment monitor report for the December quarter said.

WA Treasurer Christian Porter said the state continued to lead the nation with solid investment growth, although it was not immune to the pressures of global financial markets.

The report found 46 per cent of all projects under construction or committed to were in mining, a sector that could only thrive if the State Government could ensure ongoing investment in infrastructure and support services, Mr Porter said.

"If the present Labor commonwealth government carries the federal treasurer's threats to reduce WA's GST grant funding and to penalise growth states for earning royalty income, we will be left without means in which to ensure these sectors continue to grow," he said in a statement.