Background: Morphological and clinical characteristics are widely used to predict the success of percutaneous coronary intervention (PCI) in patients with chronic total occlusion (CTO). However, the impact of quantitative characteristics derived from coronary computed tomography angiography (CCTA) on guidewire crossing and PCI success is still unclear. This study aimed to explore the association between these quantitative characteristics and the difficulty of PCI for C'I'O. Methods: A total of 207 CTO lesions from 201 patients (84.6% male; mean age 58.9 years) with preprocedural CCTA scans who had undergone PCI for CTO were retrospectively enrolled in this case-control study. A semi-automated CCTA plaque-analysis software was adopted to obtain the total plaque volume and volume of each component according to the Hounsfield Unit (1H U) value, including dense calcium (>351 HU), fibrous (131-350 HU), fibrofatty (76-130 HU), and necrotic core (-30-75 HU) tissue. Differences in the quantitative characteristics of the CTO lesions were compared between: (I) the group of lesions with successful guidewire crossing WO minutes) and the group with failed guidewire crossing (<= 30 minutes); (II) the group of lesions with procedural success (defined as achieving residual stenosis of <= 30% and a grade 3 thrombolysis in myocardial infarction [TIMI] flow) and the group with procedural failure. Logistic regression was used to explore the association of quantitative characteristics with successful guidewire crossing in <= 30 minutes and procedural success. Results: A total of 131 (63.3%) lesions of 126 patients achieved successful guidewire crossing in <= 30 minutes and 157 (75.8%) lesions of 152 (75.6%) patients achieved procedural success. Quantitative characteristics such as occlusion length, plaque volume, volume of dense calcium, and fibrous and fibrofatty tissue showed significant differences between the groups of lesions with successful guidewire crossing in <= 30 minutes and with failed guidewire crossing in <= 30 minutes, as well as the groups of lesions with procedural success and with procedural failure. According to the results of logistic regression analysis, lower percentages of dense calcium [odds ratio (OR) =0.970, 95% confidence interval (CI): 0.950 to 0.991; P=0.004] and fibrous (OR =0.970, 95% CI: 0.949 to 0.992; P=0.007) tissue and higher percentage of necrotic core tissue (OR =1.018, 95% CI: 1.005 to 1.030; P=0.005) were significantly associated with successful guidewire crossing in <= 30 minutes. Decreased percentages of dense calcium (OR =0.969; 95% CI: 0.949 to 0.989; P=0.002) and fibrous tissue (OR =0.966, 95% CI: 0.944 to 0.990; P=0.005) and higher percentage of necrotic core tissue (OR =1.022, 95% CI: 1.008 to 1.036; P=0.002) were associated with procedural success. After adjusting for cardiovascular risk factors, the percentages of dense calcium, fibrous, and necrotic core tissue were still associated with successful guidewire crossing in <= 30 minutes, and the quantitative parameters showed consistent association with procedural success. Conclusions: Quantitative characteristics derived from CCTA for CTO are associated with successful guidewire crossing and procedural success of PCI.