Security is being increased at next week's Brisbane Ekka with extra police and security guards to be on duty.
For the first time, visitors' bags will be searched during spot checks at entry gates, barriers will be installed at all gates, and more areas of the showgrounds will be covered by CCTV.
The RNA said the measures were based on advice from the Queensland Police Service (QPS) as part of its regular review of security at the event.
An RNA spokeswoman said it has always reserved the right to check visitors' bags as a condition of entry, but this will be the first year the checks will be performed randomly at entry points.
She said the Ekka remains a safe place for people to come.
The QPS said while the national terrorism threat level was at probable, there was no known specific threat to Queensland.
In a statement, QPS said people attending the Ekka should remain vigilant but go about their lives as usual.
