The agency said it was aware of cases where Chinese applicants had been cheated by unlicensed and undeclared agents.
"Applications involving 'hidden' agents include a false declaration and often contain fraudulent documents," it said.
"We will decline those applications."
IAA registrar Andrew Galloway said the authority did not specifically record the ethnicity of immigration advisers when a complaint is received, but confirmed it had investigated complaints in the past 12 months relating to advisers targeting the Chinese community.
"The IAA cannot comment on matters currently under investigation or before court," Galloway said.
Applicants are warned that it is their responsibility to declare if someone who is not a licensed immigration adviser has assisted them with their application.
"Anyone who is not a licensed immigration adviser or exempt from licensing cannot provide immigration advice," the notice said.
It asked applicants to "be honest in your visa applications".
"Your application will not be approved if we find it contains false or misleading information and that will affect any future application you may make for a New Zealand visa."
This is the New Zealand-China Year of Tourism, which is aimed at promoting travel between the two countries.
But Statistics New Zealand figures show the number of arrivals from China has dropped by more than 3 per cent.
In June, the number of Chinese visitors fell 3.1 per cent to 18,334.