Objective:To access the clinical value and related risk factors of aortic arch calcification (AoAC) in patients with renal secondary hyperparathyroidism (SHPT) on CT during parathyroid SPECT/CT imaging.Methods:From January 2014 to May 2021, 136 renal SHPT patients (70 males, 66 females, age (50.1±11.4) years) who underwent parathyroid 99Tc m-methoxyisobutylisonitrile (MIBI) SPECT/CT in Affiliated Jiangyin Hospital of Nantong University were retrospectively enrolled. AoAC score was estimated with CT(1-5), and patients were divided into none-light AoAC group (AoAC score<3) and moderate-severe AoAC group (AoAC score≥3). Independent-sample t test or Mann-Whitney U test was used to compare differences of various indicators between two groups. Univariate binary logistic regression was used to analyze the influencing factors of AoAC. Results:Of 136 renal SHPT patients, 111(81.62%) were AoAC detected by CT. There were 84 patients in none-light AoAC group and 52 patients in moderate-severe AoAC group. The age ((46.7±9.8) vs (55.7±11.6) years; t=-4.84, P<0.001), pulse pressure (52(41, 64) vs 60(51, 70) mmHg (1 mmHg=0.133 kPa); z=-3.27, P=0.001), serum corrected calcium (2.41(2.28, 2.53) vs (2.49±0.22) mmol/L; z=-2.50, P=0.013), serum phosphorus ((1.95±0.39) vs (2.14±0.48) mmol/L; t=-2.54, P=0.012), calcium phosphorus product ((4.68±1.07) vs (5.29±1.10) mmol 2/L 2;t=-3.21, P=0.013) and parathyroid hormone (PTH) level (106.30(90.15, 127.45) vs 109.90(87.93, 157.63) pmol/L; z=-2.09, P=0.036) between non-light AoAC group and moderate-severe AoAC group were significantly different. Logistic regression analysis showed that serum phosphorus (odds ratio ( OR)=7.261, 95% CI: 2.416-21.819, P<0.001), calcium and phosphorus product ( OR=1.598, 95% CI: 1.073-2.380, P=0.021) and PTH level ( OR=1.018, 95% CI: 1.007-1.029, P=0.001) were independent risk factors of AoAC. Conclusions:Hybrid SPECT/CT can be used for an effective method of evaluating AoAC in patients with renal SHPT. High serum phosphorus, high calcium phosphorus product and high PTH level may be independent risk factors of AoAC.