Abstract: Objective:Previous reports have shown that the gene promoter region of retinoic acid receptor β (RAR β) is aberrantly methylated in cervical carcinoma, implying inhibition of gene transcription. The aim of this study was to investi-gate the association of RAR β gene expression at the mRNA and protein levels wi th cervical cancer development. Methods: We collected 37cases of fresh cervical tissues and 126 cases of formalin fixed and paraffin embedded cervical tissue spec -imens from women with cervicitis, cervical intraepithelial neoplasia (CIN) and cervical squamous cell carcinoma. Quantita -tive RT-PCR was used to detect mRNA expression and immunohistochemistry was used to assess protein expression. Results: (1) The mRNA expression of RAR β in CIN and cervical cancer was markedly decreased compared to cervicitis wi th a statistically very significant difference, and no difference was found between the mRNA levels in CIN and cervical cancer. (2) RAR β protein was expressed at normal levels in cervici tis and partial ly lost in a few cases. Wi th the development of CIN and cervical cancer, a significant loss of protein expression occurred that gradually increased (38% and 57%) and was very different from the level found in cervicitis ( P<0.01). Conclusion:In cervical cancer and i ts precancerous lesions, RAR β expression was downregulated at the transcriptional level and essential ly lost at the protein level . RAR β expression may be an important marker of cancer development. The results shown here may provide evidence for further study of the mecha-nism related to aberrant methylation of the RARβ gene and the establ ishment of a biomarker profi le for cervical cancer.