Objective:To explore the correlation between abdominal aortic calcification and serum cell division cycle 42 (CDC-42) in maintenance hemodialysis (MHD) patients, and to explore the influencing factors of them.Methods:A cross-sectional study was conducted in the Blood Purification Center of Qingdao Municipal Hospital,112 patients who underwent MHD for more than 6 months from October 2019 to March 2021 were selected. The abdominal aortic calcification score (ACCs) was calculated by reference to the abdominal lateral X flat tablets. According to AACS, 50 cases were divided into no and mild calcification group (0≤AACS<5 points) and 62 cases were divided into moderate and severe calcification group (AACS≥5 points). The level of serum CDC-42 was detected by enzyme linked immunosorbent assay (ELISA). Taking the median serum CDC-42 level as the boundary, 56 cases were divided into low CDC-42 group and high CDC-42 group. Spearman correlation analysis was used to analyze the correlation between indicators. The risk factors of elevated CDC-42 and abdominal aortic calcification in MHD patients were explored by multivariate logistic regression analysis, and the variables were included by entry method.Results:In 112 patients, 91 cases (81.25%, 91/112) had abdominal aortic calcification, and the median serum CDC-42 level was 466.56 (335.56,623.57) ng/L. CDC-42, AACs, age, dialysis age, diabetic nephropathy, glycosylated hemoglobin, alkaline phosphatase, parathormone and calcium in the no and mild calcification groups were 347.77 (291.20, 419.53) ng/L, 1.00 (0.00, 3.00) points, (57.18±6.25) years, 31.50 (15.00, 49.25) months, 34.00%(17/50), (6.63±0.97)%, 116.22 (87.32, 152.13) U/L, 258.57 (143.40, 433.31) ng/L, (2.18±0.26) mmol/L, and in the moderate to severe calcification group were 602.69 (489.61, 762.73) ng/L, 10.00 (7.00, 16.25) points, (60.81±7.12) years, 49.00 (18.00, 67.00) months, 53.23%(33/62), (7.07±1.20)%, 144.34 (99.71, 201.76) U/L, 336.57 (230.63, 506.00) ng/L,(2.28±0.26) mmol/L, with statistically significant differences between the two groups(The statistical values were 6.99, 9.11, 2.83, 2.45, 4.14, 2.08, 2.04, 2.16 and 1.99, respectively, all P<0.05). CDC-42, AACs, glycosylated hemoglobin and parathormone in the low CDC-42 group were 336.50 (295.10, 395.25) ng/L, 2.00 (0.00, 4.00) points, (6.62±1.06) %, 250.60 (140.20, 462.02) ng/L,and in the high CDC-42 group were 622.92 (558.11, 836.65) ng/L, 10.00 (6.25, 15.75) points, (7.13±1.13) %, 347.21 (240.40,501.20) ng/L, with statistically significant differences between the two groups (The statistical values are 6.51, 5.21, 2.43 and 2.54, respectively,all P<0.05). Abdominal aortic calcification has positive correlations with CDC-42 ( r s=0.704, P<0.001), age ( r s=0.308, P=0.001), dialysis years ( r s=0.198, P=0.036), glycosylated hemoglobin ( r s=0.358, P<0.001), alkaline phosphatase ( r s=0.187, P=0.048), parathormone ( r s=0.437, P<0.001), serum calciu m( r s=0.323, P=0.001) and serum phospho-rus ( r s=0.251, P=0.007), and negative correlation with serum albumin( r s=-0.276, P=0.003). This study has confirmed that high serum CDC-42 ( OR=1.010, 95%CI:1.004-1.016, P=0.001) and senior dialysis age ( OR=1.033, 95%CI:1.006-1.061, P=0.018) were independent risk factors for moderate to severe abdominal aortic calcification.Serum CDC-42 levels has positive correlation with AACs ( r s=0.704, P<0.001), age ( r s=0.240, P=0.011), dialysis age ( r s=0.191, P=0.044), glycosylated hemoglobin ( r s=0.350, P<0.001), parathormone ( r s=0.380, P<0.001) and serum calcium ( r s=0.235, P=0.013). This study learned that,high AACs ( OR=1.185, 95%CI:1.037-1.354, P=0.013) and high parathormone ( OR=1.005, 95%CI:1.001-1.009, P=0.009) were independent risk factors for high CDC-42. The area under the receiver operating characteristic curve (ROC-AUC) of serum CDC-42 in predicting moderate and severe abdominal aortic calcification in MHD patients was 0.885. When the cut-off point was 466.56 ng/L, the predictive sensitivity and specificity were 79% and 86% respectively. Conclusion:The degree of abdominal aortic calcification in MHD patients was positively correlated with the level of serum CDC-42. High serum CDC-42 and high dialysis age were independent risk factors for abdominal aortic calcification in MHD patients. High AACS and high parathyroid hormone were independent risk factors for the increase of serum CDC-42 in MHD patients .