Abstract: Objective Toinvestigate hematological parameters changes in human immunodeficiency virus (HIV) positive patients taking active antiretroviral treatment and explore its clinical significance. Methods One hundredHIV positive patients admittedtoour hospital fromNovember 2013 toDecember 2014 were enrolledin this study, and they were dividedintotwogroups: highly active antiretroviral therapy (HAART) group(n=55) and HARRT na ve group(n=45). The levels of peripheral bloodCD3⁺, CD3⁺ CD4⁺ and CD3⁺CD8⁺ T-lymphocytes were detectedby flowcytometry. WBC, RBC, Hgb, HCT, MCV, MCH, MCHC, RDW, PLT, and MPV were determinedby nucleic acidfluorescent dye methodand flowcytometry. PT and PTA levels were detectedby immunoturbidimetry. HIVRNA were determinedby fluorescent quantitation PCR methods, and the characteristics of hematological parameters in HIV positive patients taking active antiretroviral treatment were observed. Results There was nostatistically significant difference between observation groupand control groupin hematology indexes (P＞ 0.05). Prevalence of anemia, leucopenia, thrombocytopenia, neutropenia and lymphopenia were 12.0%, 36.0%, 4.0%, 28.0% and 5.3% in patients taking HAART and 30.7%, 16.9%, 9.2%, 13.8% and 4.6% in HAART na ve patients respectively. There were significant differences in total WBC, RBC, Hgb, MCV, MCH, MCHC, MPV and CD4 counts between patients taking HAART and HAART na ve patients (P＜ 0.05). Conclusion HAART can reduce the incidence of anemia and thrombocytopenia in patients with HIV, but it is prone tohave leucopenia, neutropenia and lymphopenia. Clinicians needtotake consideration about drug combination, course of treatment and treatment tabooin HIV positive patients according tochanges of hematological indexes.