Objectives: To determine factors associated with late and delayed antiretroviral therapy (ART) initiation in China and provide evidence for HIV prevention. Methods: Logistics regression model was used to determine factors associated with three outcomes: late (CD4 cell count <200 cells/µL or clinical AIDS diagnosis prior to ART initiation), delayed (more than 1 month between HIV diagnosis date and ART initiation) and either late or delayed ART initiation. Results: Multivariable analysis revealed that male, heterosexual, HIV diagnosis before 2014, HBV/HCV seropositive, and tuberculosis were associated with increased odds of all three outcomes. Conversely, married or cohabiting patients were less likely to have delayed ART initiation and either late or delayed ART initiation, while people who inject drugs were more likely to have these two outcomes. Additionally, older age was associated with an increased risk of having either late or delayed ART initiation, but a decreased risk of delayed ART initiation. Conclusion: The proportion of late and delayed ART initiation decreased significantly after the release of the 2016 guidelines in China. To further improve late diagnosis and early treatment, precise interventions for key populations are required.