This paper reported the first case of thoracic infection caused by Neisseria elongata in China. MALDI-TOF Vitek MS system, VITEK 2 Compact automatic microbial analysis system and molecular sequencing technology were used to identify and analyze the isolated strains. Drug susceptible test of the isolated strains was performed by K-B method and E-Test method, and the break point interpretation was carried out according to the reference of Clinical and Laboratory Standards Institute (CLSI) for Neisseria meningitidis. The biological characteristics and diagnosis and treatment process of Neisseria elongata were analyzed to improve the attention of microbiological staff to rare pathogens, and to provide experimental evidences for clinical diagnosis and treatment.