Aminolaevulinic Acid Photodynamic Therapy for HPV+ Low Grade Cervical Intraepithelial Neoplasia (LSIL;CIN1)

Inclusion Criteria: * Premenopausal women, 25-50 years of age * Diagnosed with LSIL/CIN1 by local pathology (biopsy) and high-risk HPV positive by HC2 assay within the last 3 months * Satisfactory colposcopy examination (visibility of entire transformation zone and entire lesion margin ) * Meet the following conditions: pregnancy test negative; no pregnancy plan during the trial; no sexuality or reliable contraceptive measures taken since last menstruation to the onset of the study, agreeing to adopt reliable contraceptive measures during the study * Written informed consent signed Exclusion Criteria: * ASC-H (atypical squamous cells, cannot exclude HSIL) or HSIL (high-grade squamous intraepithelial lesions) or AGC (atypical glandular cells) or AIS (adenocarcinoma in situ) on cytology, or malignant cells on cytology or histology, or other suspicion of either micro-invasive or invasive disease * Invasive carcinoma possibility or lesions extending to the vaginal vault or suspicion of endocervical disease on colposcopy * Severe pelvic inflammatory disease, severe cervicitis, or other severe gynaecological infection as per clinical examination * Undiagnosed vaginal bleeding * With allergic disease at present; known or suspected porphyria; known allergy to ALA or analogues * With serious cardiovascular, neurologic, psychiatric, endocrine, hematological disease; immunocompromised conditions; patients with malignant tumors * Hepatic or renal functions abnormal (alanine aminotransferase or aspartate transaminase or total bilirubin \> 1.5 upper limit of normal \[ULN\], or serum creatinine or blood urea nitrogen \> 1.5 ULN) * Pregnancy or nursing * Previous physical therapy of LSIL/CIN1 after pathologic diagnosis * Participation in any clinical studies within the last 30 days * Subjects that the investigators judged to be not suitable to participate the study besides above