BACKGROUND: Infectious 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. METHODS: From 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. FINDINGS: The 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. INTERPRETATION: Infectious diseases were common in Chinese adults. The observed burden of, and disparities in, site-specific infections can inform targeted prevention efforts. FUNDING: Kadoorie Foundation, Wellcome Trust, MRC, BHF, CR-UK, MoST, NNSF.