Background: There has been a global consensus since 2016 that antiretroviral therapy (ART) should be initiated following HIV diagnosis regardless of CD4-count test results. Identifying an instrument that is able to accurately assess the readiness of HIV-infected persons for treatment initiation is thus critical. Purpose: (1) To evaluate the comparative readiness of patients receiving ART and those who are not yet on ART; (2) to evaluate the respective readiness variation within these 2 groups over a one-year period; and (3) to identify the cutoff value for medication readiness that indicates the ideal time to initiate ART. Method: A multicenter cohort study design was conducted and 297 newly diagnosed patients with HIV were enrolled at four time points, including: baseline and at 1, 3-6, and 9-12 months after ART initiation. Data collection included a demographics datasheet, the Chinese version of the HIV Medication Readiness Scale (HMRS), and 2 items, readiness to take ART for a long period of time and confidence in adhering to ART, which were scored using a 10-point Likert scale. Results: Overall, 224 (75.4%) of the participants had initiated ART. Over time, the medication readiness of participants with ART initiation had increased significantly over that of non-ART user (p < .001). The mean scores of the 2-item self-rated readiness scale for patients with ART initiation were significantly greater than those without (p < .001). The cutoff values for HMRS, self-rating readiness for ART, and confidence in adherence to ART were 23.5, 5.5, and 6.5, respectively. Conclusions/Implications for Practice: The optimal cutoff value of the Chinese version HMRS for evaluating HAART initiation among persons with HIV infection was 23.5. HIV healthcare professionals may apply the Chinese version HMRS and the two simple self-rated items as a clinical tool for quickly assessing the initiation of ART in people living with HIV.