The progression of cin grade I to grade III is usually 1 to 2 years without therapeutic intervention. With therapeutic intervention it may get better and the disease progresses slowly, so the time for cin grade I to grade III varies from person to person. Cin grade I refers to endomatous lesions of the cervical epithelium, which are the lowest grade lesions, and cin grade III is the highest grade lesions of the cervical epithelium, also known as precancerous lesions of the cervix. When cin grade I is found and given medication, it may get better and the condition will not continue to develop further, but if it is not treated and accompanied by HPV infection, the condition will continue to develop and usually turn into cin grade III in 1 to 2 years. Cervical lesions is a long-term development process, lesions early, must be timely treatment to prevent the lesions continue to develop, try to avoid cervical cancer.