Doctors can make preliminary judgments based on patients’ clinical symptoms. Pneumonia with novel coronavirus infection is mainly manifested by fever, malaise and dry cough; a few patients have symptoms such as nasal congestion, runny nose and diarrhea. If symptoms such as respiratory symptoms, fever, chills, malaise, diarrhea, and conjunctival congestion are present, prompt medical investigation is required. For the basis of meeting the criteria of suspected cases, laboratory tests can be performed to aid in diagnosis. Positive nucleic acid detection of novel coronavirus by real-time fluorescence RT-PCR of respiratory specimens or blood specimens, or viral gene sequencing of respiratory specimens or blood specimens, which are highly homologous with known novel coronaviruses, can confirm the diagnosis.