Abstract: Objective：To explore the value of 320row CT variable helical pitch (VHP) technique applied in preoperative evaluation of transcatherter aortic valve replacement (TAVR). Methods：From Jan. 2016 to Apr. 2018, 320row CT angiography was performed in 54 patients before transcatherter aortic valve replacement (TAVR, and the data were analyzed retrospectively. CT scanning range is from thorax entrance to the level of the middle segment of the femur. Shortpith spiral electrocardiography (ECG)gated scanning was utilized to examine the level from thorax entrance to the heart bottom, while highpith spiral nonECGgated scanning was used for the level from heart bottom to middle segment of the femur. Scanning parameters were shown as follows: 120 kV tube voltage, auto tube current, 0.5 mm/0.3 mm thickness/spacing, 90100 mL contrast, and 4~5 mL/s flow rate. The reconstructed phases were 30%, 40%, and 75%, respectively. The control group of 32 patients underwent a largescale fullgated scanning. The scanning range, scanning conditions, reconstruction parameters and contrast agent dosage were the same as those of the experimental group. Results：CT scanning was performed successfully in 53 patients who could hold their breath. However, one case failed because of the breath. High quality image of aortic valve and coronary diagnostic information could be observed. Largerange nonECGgated scanning could show all the entrances of peripheral blood vessels. Conclusions：The VHP technique is feasible for preoperative evaluation of TAVR and aortic valve, and enables large range CT scanning of the entire aorta with less contrast. However, the disadvantage is that VHP technique needs to hold breath when using ECGgated scanning with higher radiation dose.