A colloid gold strip (CGS) test for detecting antibodies to H5 subtype Avian Influenza Virus (AIV) was developed. The test is based on membrane chromatography and uses colloidal gold conjugated with inactivated AIV-H5N1 as the tracer. On the test strip, a baculovirus expressed haemagglutinin (HA) protein was used as the capture complex at the "test line", and anti-HA monoclonal antibody was used as the capture antibody at the "control line". The assembled test strip was housed in a plastic case. Compared with the hemagglutination inhibition test, the sensitivity and specificity of the CGS test were 88.8% and 97.6%, respectively, in detecting H5N1 antibodies in 830 serum samples from vaccinated chickens. Because it is rapid and does not require specialized equipment or technicians, the CGS test should be useful for detecting H5N1 antibodies in the field.