Abstract: Objective Patients with primary membrous nephropathy(PMN) have an elevated risk of venous thromboembolism (VTE). The aim of this study was to detect plasma level of ADAMTS13 in PMN patients complicated and uncomplicated by VTE and examine their clinical significance. Methods From September 2019 to September 2021, 60 PMN patients were recruited and assigned into two groups of complicated by VTE(PMN-VTE) and not complicated by VTE(PMN-notVTE) (n=30 each). And 30 healthy adults were selected as normal control group. Plasma level of von Willebrand factor(vWF) and its cleaving protease ADAMTS13 were measured by enzyme-linked immunosorbent assay(ELISA). Results ADAMTS13 level was significantly lower in PMN than normal control group. Additionally, level of ADAMTS13 was significantly lower in PMN-VTE group than PMNnot-VTE group while level of vWF and ratio of vWF/AMADTS13 were significantly higher in PMNVTE group. Furthermore, ADAMTS13 level was correlated positively with plasma albumin(r=0.539, P<0.01) and negatively with vWF, 24-hour urinary protein, cholesterol, low density lipoprotein, fibrinogen, D-dimer, serum creatinine and interleukin-6. However, no association existed between levels of ADAMTS13 and PLA2R-Ab. And area of under ROC curve was 0.794 (P<0.001) for ADAMTS13 diagnosing PMN with concurrent VTE and the optimal threshold value was 65.95% with a sensitivity of 96.7% and a specificity of 53.3%. And vWF/ADAMTS13 was 0.831(P<0.001) and the optimal threshold value was 2.63 with a sensitivity of 86.7% and a specificity of 66.7%. Conclusion ADAMTS13 level declines not only in PMN but also drops more in PMN complicated by VTE. Furthermore a decline of ADAMTS13 level may be correlated with kidney function, inflammatory factor, blood lipid and hypercoagulable state. No significant difference was detected for PLA2R-Ab. And detecting plasma ADAMTS13 level is expected to predict PMN complicated by VTE while the ratio may be more predictive.