Transmissible gastroenteritis virus (TGEV) is a member of the coronaviruses. The viral spike (S) protein of TGEV mediates interaction between TGEV and its susceptible cells. Herein, DNA plasmid bearing TGEV S1 gene (the N terminal half of TGEV S gene) was used to immunize BALB/c mice followed by generation of a monoclonal antibody (MAb) using the hybridoma technique. The generated MAb (1H4) was identified by ELISA. Immunofluorescence assays showed that MAb 1H4 was able to detect infection of cells with TGEV. The MAb 1H4 distinguished TGEV from other control viruses. Additionally, although the type of MAb 1H4 was IgM, it could reduce cell infection by TGEV in a dose-dependent manner.