Background <p>This study aimed to describe the epidemiological trends and regional/age distributions of HIV and AIDS in China from 2005 to 2020 and provide scientific reference for the government about HIV and AIDS prevention and control.</p> Methods <p>Data on HIV and AIDS cases reported encompassing various age groups and 31 provinces, autonomous regions, and municipalities in mainland China from 2005 to 2020 were sourced from the Data Center of China Public Health Science.</p> Results <p>A total of 570,576 AIDS cases were identified and reported in China from 2005 to 2020. The reported AIDS incidence, AIDS-related mortality, HIV incidence, and HIV mortality increased from 0.4324/100,000, 0.1012/100,000, 1.9437/100,000, and 0.0216/100,000 in 2005, respectively, to 4.4283/100,000, 1.3405/100,000, 6.3839/100,000, and 1.2884/100,000 in 2020, respectively. The corresponding average annual growth rates were 16.33%, 18.19%, 7.83%, and 29.40%. The reported HIV and AIDS stage-specific incidence and mortality significantly differed by geography and age. The reported HIV incidence peaked among young adults (20–34 years old), and the &gt; 50 age group showed the highest HIV mortality, AIDS-related mortality and AIDS incidence.</p> Conclusions <p>The HIV and AIDS epidemic in China showed a gradual rising trend over the years and exhibited geographical and age distribution difference. Young adults and older populations were the major populations in the HIV and AIDS epidemic in China. Health education, interventions, and testing efforts targeting these key populations should be strengthened. Building a resilient HIV and AIDS treatment service system is essential for ensuring stable HIV and AIDS services during public health emergencies.</p> Clinical trial number <p>Not applicable.</p>