Abstract: ISalmonella/I Typhi and ISalmonella/I Paratyphi are the pathogens to cause enteric fever, which remains serious threat to human heath in developing countries. It is difficult to distinguish typhoid fever from paratyphoid fever based on clinical symptoms, so the etiological detection and differential diagnosis are needed. This paper summaries laboratory detection methods for the diagnosis of typhoid fever, including pathogen isolation, serological test and PCR, and several multiplex PCR for the differential diagnosis of typhoid fever and ISalmonella/I Paratyphi A infection. Multiplex PCR can be used for the amplification of rfb cluster gene, O antigen, Vi antigen, flagellin coding genes and other specific genes of ISalmonella/I Typhi and ISalmonella/I Paratyphi A for the differential purpose.