In order to test the detection sensitivity and specificity of the COVID-19 IgG-IgM combined antibody test, blood samples were collected from COVID-19 patients from multiple hospitals and Chinese CDC laboratories. The tests were done separately at each site. A total of 525 cases were tested: 397 (positive) clinically confirmed (including PCR test) Covid-19-infected patients and 128 non-Covid-19-infected patients (128 negatives). The testing results of vein blood without viral inactivation were summarized in Table 1. Of the 397 blood sample from Covid-19-infected patients, 352 tested positive, resulting in a sensitivity of 88.66%. Twelve of the blood samples from the 128 non-Covid-19 infection patients tested positive, generating a specificity of 90.63%.