Squamous epithelial cell carcinoma antigen is a tumor glycoprotein-associated antigen isolated from squamous epithelial cell carcinoma of the uterine cervix with a molecular weight of 48,000. squamous epithelial cell carcinoma antigen is commonly detected by RIA and ELISA, which have significantly higher sensitivities. The normal threshold in plasma is 1.5ug/l. Squamous epithelial cell carcinoma antigen (SCCA) is highly specific for the vast majority of squamous epithelial cell carcinomas. SCCA is elevated in over 70% of patients with squamous cervical carcinoma; 15% of patients with cervical adenocarcinoma; and 40-50% sensitivity for vulvar and vaginal squamous epithelial cell carcinomas. The SCCA is used in clinical practice as an indicator of the efficacy of cervical cancer. When the SCCA decreases gradually after treatment, it is considered to be effective; when it continues to increase, it is considered that the chemotherapy regimen is not suitable for this patient and the treatment regimen needs to be changed. This antigen also has a certain reference value for patients with recurrence. Therefore, SCCA is useful for tumor patients to judge prognosis and monitor disease development. Squamous epithelial cell carcinoma antigen is a tumor marker. A high value of SCCA does not necessarily mean malignant tumor, but needs to be analyzed together with clinical symptoms and other examinations. It is necessary to review squamous epithelial cell carcinoma antigen in hospital regularly to observe the change of value.