BackgroundInfectious diseases remain a major global health concern, including in China, with an estimated >10 million cases of infectious disease in 2019. We describe the burden of site-specific infectious diseases among Chinese adults. MethodsFrom 2004 to 2008, the prospective China Kadoorie Biobank enrolled 512,726 adults aged 30-79 years from 10 diverse areas (5 rural, 5 urban) of China. During the 12 years of follow-up, 101,673 participants were hospitalised for any infectious disease. Descriptive analyses examined standardised incidence, mortality, and case fatality of infections. FindingsThe incidence of any infectious disease was 1856 per 100,000 person-years; respiratory tract infections (1069) were most common. The infectious disease mortality rate was 31.8 per 100,000 person years (20.3 and 9.4 for respiratory and non-respiratory infections, respectively) and case fatality was 2.2% (2.6% and 1.6% for respiratory and non-respiratory infections, respectively). Infectious disease incidence and mortality rates were higher at older ages and in rural areas. There were no clear sex-differences in infectious disease incidence rates, but mortality and case fatality rates were twice as high in men as in women. InterpretationInfectious diseases were common in Chinese adults. The observed burden of, and disparities in, site-specific infections can inform targeted prevention efforts. FundingKadoorie Foundation, Wellcome Trust, MRC, BHF, CR-UK, MoST, NNSF