The spike（S） protein is a major membrane protein of the SARS-CoV

which plays an important role in receptor interaction

immune recognition and inducing neutralizing antibody.In this study

three nonoverlapping fragments（151 -1 200 bp

1 201-2 250 bp

and 2 251-3 150 bp） of the S gene were amplified by PCR

cloned in pET-32a and expressed in Escherichia coli.Recombinant proteins were confirmed by western blotting and were used as antigens for immunization of BALB/c mice.Immunizations were performed three times intranasally or intraperitoneally.Serum and lung extracts of immunized mice were collected and tested by enzyme-linked immunosorbent assays（ELISA） for S protein specific IgG or IgA antibodies.The results indicated that the S protein could stimulate IgA antibodies in the lung mucosal tissue as well as IgG antibodies in the serum by intranasal immunization.Further more

we found the predominant antigenic regions of the S protein for mucosal immune response mainly located in amino acid residues from 401 to 750.