Four different immunoassays based on the same generic polyclonal antibody were validated by high performance liquid chromatography, respectively. They also were compared with each other in terms of sensitivity, precision, and accuracy for the quantification or screening of sulfonamide residues in food samples. Correlation studies showed that there was a good correlation between the immunoassays and liquid chromatography data. The conventional plate assay has better precision and the plate-enhanced chemiluminescent assay has higher sensitivity. These two methods all could be used as quantification methods for large numbers of samples and complements of the conventional analytical methods in laboratory. The flow-through strip assay has higher sensitivity and the dip-stick strip assay was less affected by matrix effect. These two methods all could be used as valuable tools for the rapid on-site screening of sulfonamide residues in animal-derived food samples.