Colposcopic staining without coloration may be characteristic of abnormal squamous epithelial differentiation. Normal or mature differentiated squamous epithelium is rich in glycogen in the middle and superficial cytoplasm and can be stained brown or black by compound iodine solution. If there is no coloration (positive), further cervical cancer screening can be done, as well as cervical biopsy, which can lead to early diagnosis, treatment and recovery. If it is a malignant lesion, it can be cured at an early stage. In addition, colposcopic staining without coloring is also a manifestation of inflammation, and there may be postmenopausal or estrogen deficiency, congenital transformation zone of the possibility, no need to worry too much. In the clinic, it is recommended that women with normal sex life should have cervical cancer screening once a year.