Acetic acid whitening test is the most basic operation in colposcopy, the surface of the cervical erosion in a certain concentration of acetic acid solution infiltration for one minute, the surface of the erosion will show a layer of thin and white phenomenon, like a thin white cloud in the sky, this phenomenon is normal. If the white color of the vinegar white test obviously protrudes from the surface, like a thick white cloud, commonly known as lard-like, may be pre-cancerous lesions of the cervix or the early stage of cervical cancer, the need to do cervical histopathology to make a clear diagnosis. If the vulvar or cervical redundant organisms of the vinegar white test is obvious white, it may be condyloma acuminatum, and need to consult a doctor.