Abstract: Objective: To explore the application of 64-slice spiral computed tomography perfusion imaging (CTPI) in evaluating angiogenesis in human osteosarcoma.Methods:Twenty-six patients (18males and 8 females ranging from 9 to 56 years old, with an average of 19 years) with osteosarcoma underwent 64-slice spiral CTPI. We analyzed the correlations of CTPI parameters including blood flow (BF), blood volume (BV), time to peak (TTP), and permeability surface (PS) with the expression of markers of angiogenesis. Statistical analysis was performed with paired-samples t test, and Pearson correlation analysis was employed to investigate the correlations of CTPI parameterts with MVD.Results: Mean BF, BV, TTP, and PS values of osteosarcoma group were 46.6mL/100 g/min ±25.1 (standard deviation), 61.8 mL/100 g ± 29.5, 122 .9 seconds±26.2, and 44.5 mL/100 g/min ±14.6, respectively. Those in the normal muscle group were 5.2 ± 6.6mL/ 100 g/min, 9.6 ± 7.3mL/100 g, 115 .5 ± 33.1 and 17.0 ± 29.3mL/100 g/min, respectively. Osteosarcoma group showed higher BF,BV and PS compared with the normal muscle group (P=0.000 , P=0.000 , and P=0.000 ). However, no significant difference was found in TTP between osteosarcoma tissue and normal adjacent muscle tissue ( P=0.273 ). BF, BV, and PS were positively correlated with MVD (r=0.83, P=0.000 ; r= 0.87, P=0.000 ; and r=0.63, P=0.001 ). No correlation was found between TTP and MVD (r=- 0.02, P=0.93). Conclusion:CTPI is useful for assessing tumor vascularity of osteosarcoma and CTPI parameters are positively correlated with MVD.