Abstract： Objective To analyze the base situation and influential factors of late diagnosis among newly identified HIV/AIDS cases in Anhui Province from 2011 to 2015.Methods Database information of the newly identified HIV/AIDS cases in Anhui Province from 2011 to 2015 were downloaded from the National HIV/AIDS Comprehensive Information System of China's disease prevention and control information system. To analyze the data including basic information, sample source, route of HIV transmission, population mobility, venereal disease, death and first CD4 count; and the number of 7 073 cases were classified according to late diagnosis and non-late diagnosis criteria. The Chi-square test and logistic regression analysis were used to analyze the influential factors of HIV late diagnosis. Results A total of 7 073 newly identified HIV/AIDS cases were analyzed,and the mean age was(38.5±15.0)years.The proportion of late diagnosis in all counted cases was 41.7% (2 949/7 073); from 2011 to 2015, the proportions of late diagnosis were 59.7% (485/812), 46.5% (531/1 141), 42.7% (587/1 376), 36.1% (609/1 686), and 35.8% (737/2 058), respectively. Compared with the 0 to 19 years group, the 40 to 59 years group and over 60 years old group have higher risk of late diagnosis(OR=2.68,95%CI:1.94-3.71;OR=2.18, 95%CI:1.53-3.10,respectively).Compared with the high education group,the illiterate and primary school education group have higher risk of late diagnosis(OR=1.74,95% CI:1.36-2.22;OR=1.64,95% CI:1.34-2.01, respectively). Compared with other sample sources, medical institutions have higher risk of late diagnosis (OR=2.64, 95% CI: 2.28-3.05). Compared with migrant population, the resident population have higher risk of late diagnosis(OR=1.80,95% CI:1.53-2.11).Conclusion The proportion of late diagnosis among newly identified HIV/AIDS cases in Anhui province was relatively high from 2011 to 2015.The main risk factors of late diagnosis included cases reported by medical institutions, resident population, over 40 years old age group and low education level.