Abstract: The active group carboxyl was introduced to Chloramphenicol(CAP) and formed CAP half succinaate(CAP-HS) which has hapten structure by chemical modification. The method of mixed anhydride(MA) was used to conjugate CAP-HS to BSA and obtained artificial immunogen BSA-CAP-HS, the coating antigen OVA-CAP-HS was obtained in the same way. IR, UV and SDS-PAGE were used to identify BSA-CAP-HS. New Zealand white rabbits and SPF chickens were immunized with BSA-CAP-HS，the titre of polyclonal antibody(pAb) was detected by indirect ELISA, the sensitivity of pAb was identified by blocking ELISA and the specificity of pAb was identified by test of agar bidirectional pervasion, WestGold immunochromatography and cross-reaction. The results showed that BSA-CAP-HS had been synthesized successfully and its conjugation ratio of CAP-HS to BSA was about 15.6∶1, the high-titer, sensitive and specific CAP pAb had been produced in sera of immunized New Zealand white rabbits and SPF chickens, which made it possible to establish immunoassay of CAP residues in feed and animal food.