Premier Mark McGowan has taken aim at what he called a "national move" to undermine Australia's relationship with the People's Republic of China, saying it was the most dangerous threat to WA's economy.

The comments come amid a controversy facing federal Liberal MP Gladys Liu over her alleged membership of groups linked to the Chinese Communist Party and after the Premier was himself forced to defend WA Labor MP Pierre Yang for failing to disclose links to pro-Beijing organisations.

WA Premier Mark McGowan addressing the state's Property Council on Wednesay morning.

In a speech to WA's Property Council, Mr McGowan said WA was the biggest trading state in the nation and most of that trade was with China.

"If I can make one plea to this audience full of very significant people in Western Australia and Australia: keeping our relationship strong with China is extremely important and we shouldn't throw it away," he said.