Abstract: The purified recombinant dNcSRS2 protein was used as coating antigen to establish an indirect ELISA for detecting antibody against Neospora caninum. Commercially available diagnostic kits (IFAT and two commercial ELISA kits) for N. caninum were chosed as the reference standard methods. The results showed that the ELISA method was highly sensitive, specific and reproducible. The agreements between the methods were above 92%. Dairy cattle sera (n=236) were tested for antibodies to N. caninum; out of which 22% reacted positively. This is the first use of recombinant protein establishing diagnostic method in China. The new ELISA using dNcSRS2 could be used for mass screening of the prevalence of N. caninum infection in diary cattle.