This paper describes the study of atomization of nanoparticlesby inductively coupled plasma mass spectrometry (ICPMS) and developes a novel nonisotopic immunoassayby coupling sandwich-type immunoreaction to ICPMS. The goat-anti-rabbit immunoglobulin G (IgG) labeled with colloidal gold nanoparticles served as ananalyte in ICPMS for the indirect measurement of rabbitanti-human IgG. Matrix effect studies showed the goldsignal was not sensitive to the organic matrix. A relativelygood correlation (r2=0.9528) between the proposedmethod and enzyme-linked immunosorbent assay hasbeen obtained. The method may have significant potentialas an important ICPMS-based nonisotopic immnoassaymethod for the simultaneous determination of biologicanalytes of interest by labeling different kinds of inorganicnanoparticles.