The performance of endocervical curettage (ECC) is a dispute in population screening programs. Data of 3,460 women referred to colposcopy examination and had completed pathological results in the Shanxi Province Cervical Cancer Screening Study I and II were reviewed. Among them, 0.6% and 2.7% women were identified as the histopathological confirmed high-grade squamous intraepithelial lesion or worse (HSIL+) by ECC alone or both ECC and quadrants biopsy respectively. Age, cytology, and colposcopy impression are the impact factors for the HSIL+ yield of ECC (P<0.05). The age-adjusted odds ratio for cytology and colposcopic impression were 5.283 (95% CI: 3.989-6.997) and 3.609 (95% CI: 2.910-4.476) respectively. In low-grade squamous intraepithelial lesion cytology and abnormal colposcopy, no additional HSIL+ was found by ECC. In low-grade squamous intraepithelial lesion cytology but normal colposcopy, the additional yield was 0.6%, 0.8% and 1.1% for the three age groups respectively. In high-grade squamous intraepithelial lesion or worse cytology, the additional HSIL+ yield by ECC ranged between 1.4% and 6.6%. We conclude that the performance of ECC increases with age, the severity of cytology, and colposcopic impression. For women 35 years and older, ECC should be performed if the cytological finding is high-grade or worse in cervical cancer screening program.