Abstract: Objective: To investigate the potential of CT-enhanced quantitative parameters for preoperative prediction of WHO/ISUP grading for renal clear cell carcinoma (ccRCC). Methods: The study involved collecting clinical and CT-enhanced data of 98 patients with ccRCC, who were then classified into low level group (76 cases) and high level group (22 cases) based on the WHO/ISUP classification. Differences in CT-enhanced quantitative parameters between the two groups were compared, and the diagnostic efficacy of each parameter for predicting ccRCC WHO/ISUP grading was evaluated. External verification was conducted to identify CT-enhanced quantitative parameters with the best generalization ability. Results: There were significant differences in the CT value, net increment, and enhancement rate in both cortical and substantive phases between the two groups. The AUC values were 0.834, 0.871, 0.900, 0.707, 0.678, and 0.762, respectively. The cut-off values were 123.5 HU, 71 HU, 0.73, 87.5 HU, 54 HU, 0.67, respectively. The diagnostic efficacy of cortical enhancement rate was the highest with an AUC of 0.900, a sensitivity of 0.842, and a specificity of 0.864. The external validation results revealed that the diagnostic efficacy of cortical phase enhancement rate (AUC=0.867) was better than that of cortical phase CT (AUC=0.735) and cortical phase net increment (AUC=0.709). The Z values were 2.134 and 2.417, respectively. Conclusion: The quantitative parameters of CT enhancement can be used to predict ccRCC WHO/ISUP grading. Cortical phase enhancement rate is the parameter with the highest diagnostic efficiency and the best generalization ability.