Abstract: Using the purified Cap recombinant protein as coating antigen of indirect ELISA,detecting kit was developed by the optimal reaction conditions of ELISA. In comparative experiments with commercial ELISA kit for detection of 55 serum samples, the sensitivity, specificity and coincidence rate of the established ELISA method were 95.12%，92.86% and 94.55% respectively. The established ELISA method had no cross-reactivity with the reference sera of other swine viruses (PCV1, CSFV, PRRSV, PPV, PRV). The intra-assay variation coefficient was 2.3% to 4.5%, inter-assay variation coefficient was 1.12% to 2.63% respectively. The ELISA antibody detection kit could be stable at －20 ℃ at least for one year. 66 serum samples of three pig farms from Anhui, Guangdong, Guangxi were detected by detection kit, and the positive rate was 100%, 48.39%, 100% respectively.

Key words: porcine circovirus serotype 2; capsid protein; indirect ELISA; antibody detection kit