Abstract: Objective To analyze the late detection of newly reported human immunodeficiency virus(HIV)infected people and acquired immune deficiency syndrome(AIDS)patients in Suining City of Sichuan Province. Methods The newly reported HIV infected and AIDS cases in Suining City of Sichuan Province from Chinese Disease Prevention and Control Information system were screened out, ratios of late detection patients with different demographic characteristics according to the current definition standard of late detection used in China were calculated. Results There were 1 251 newly reported HIV infected people and AIDS patients in Suining City of Sichuan Province in 2019, among whom 497 cases were found to be late discovered. The late detection rates of males and patients aged 45 years and above were higher than those of females and aged below 45 years, respectively; the late detection rate of patients with education background of college and above was lower than those with education level of high school and below; farmers, migrant workers and workers had higher late detection rate than the other occupations; heterosexual transmission had higher late detection rate than the other transmission methods; hospital-derived test samples had higher late detection rate than the other sample sources. Gender, age, education level, occupation, transmission route and sample source were influencing factors of late detection rate(P<0.05), and marriage status and regional distribution has little effect on the late discovery rate(P>0.05). Conclusion The overall late detection rates of newly reported HIV infected and AIDS cases in Suining City of Sichuan Province in 2019 are relatively high. - Late detection is related to factors such as gender, age, education, occupation, transmission route and sample source.