Abstract: Objective: To explore the application value of CT bilateral lower extremity volume measurement in the grading of secondary lower extremity lymphedema. Materials and methods: Patients with secondary lower extremity lymphedema who were admitted to our hospital and underwent CT of both lower extremities were collected from June 2019 to January 2020. The clinician completed the multiple-circumference measurement of lower extremity within one week of CT scanning, and recorded the volumes of both lower extremities, thighs and calfs obtained by CT bilateral lower extremity volume measurement and clinical multiple-circumference method, respectively. Based on the percentage enlargement in the volume of the affected side compared with the healthy side, the grading of the whole lower extremity, thigh and calf was obtained by CT and clinical measurement results,respectively. Kappa analysis was used to compare the consistency between CT and clinical in the grading of whole lower extremity. Results: Thirty-eight patients were finally enrolled. The volumes of lower extremities measured respectively by CT bilateral lower extremity volume measurement and clinical multiple-circumference method were (cm³): the affected side (9984±2217 and 11308±2373), the healthy side (7154±1417 and 8265±1704). The CT grading of whole lower extremity was 1 case in preclinical stage, 6 cases of mild, 14 cases of moderate, and 17 cases of severe. The clinical grading of whole lower extremity was 1 case in preclinical stage, 8 cases of mild, 11 cases of moderate, and 18 cases of severe. The consistency between CT and clinical in grading of whole lower extremity is excellent (Kappa=0.878). Conclusion: CT bilateral lower extremity volume measurement can be used as an imaging tool in the grading of secondary lower extremity lymphedema.