Purpose To explore the practical significance of TERC gene amplification by fluorescence in situ hybridization ( FISH) on the differential diagnosis of cervical intraepithelial neoplasias 1 and 2 by tissue microarray. Methods A total of 42 cases of cervical tissue samples were selected, including 20 cases of normal cervix, 22 cases of cervical intraepithelial neoplasia (CIN) 1/2 (8 cases of CIN1 and 14 CIN2). Homemade tissue microarray was prepared. TERC gene amplification was detected with FISH method. Results TERC gene showed no amplification in the normal cervical squamous epithelium. TERC gene amplification was detected in 22. 7%(5/22)CIN1 and 77. 3%(17/22) in CIN2. 1/8 cases of TERC gene amplification in CIN1, 4/14 cases of TERC gene amplification in CIN2. There were significant differences in TERC gene amplification between those groups (P<0. 05). Conclusion The method is feasible and reliable in the detection of TERC gene amplification in CIN1/2 on paraffin sections. It has practical values in differential diagnosis between CIN1 and CIN2.