Abstract: This article reviews technical development of antibody and antigen preparation and application methods of a handful of major immunoassay (radioimmunoassay,enzyme immunoassay,fluorescence immunoassay,chemiluminescence immunoassay,etc.)in the analysis of pesticide residues.With special emphasis on new formats developed in recent years,including coupled immunoassay and chromatography technique,a new tendency of trace analyses is introduced in detail.Underlying problems in the application of immunoassay are highlighted and future trends of immunoassay development postulated.