Abstract: To develop immunochemical methods for analysing sulfonamides residues,sulfamerazine(SM) and sulfamethazine(SM2) were chemically linked to carrier proteins(bovine serum albumin,BSA and ovalbumin,OVA) in such way that their aromatic amino group,common to all sulfonamides,was diazotized and linked to carriers or was directly linked to carriers by glutaraldehyde.5 hybridomas against sulfamerazine and 18 against sulfamethazine were prepared and characterized,in which involved their karyotypes,subclasses and light chain types,reactivity of heterologous antigen-coated ELISA,and competitive reactivity to SM or SM2,and cross-reactivity with structural analogues.Among them,11C8 antibody against SM,which the IC50 that combined competitively with SM was 14.1 μg/L,showed cross-reactivity not more than 20% to SM2 and less than 10% or more to the rest,and six antibodies,which IC50 were from 38.8 μg/L to 70.0 μg/L were chosen from 18 antibodies against SM2.Five out of them,which were 2B7,4D5,13C9,14C5 and 16C2 antibodies,showed significant cross-reactivity(73.5%～132.9%),but antibody 15D10 showed very little cross-reactivity(<5%) towards SM2.Therefore,basic on this research,these antibodies towards SM or SM2 could be used in immunological research and application for sulfonamides residues analysis.