A human cervical cancer cell line, CX, was established from a patient with squamous cell carcinoma of the uterine cervix. The CX cells were epithelial in morphology with relatively large vesicular nuclei, and prominent nucleoli. Cytoplasmic organelles were generally sparse but tonofilaments were relatively abundant. The cells grew as a compact sheet with close membrane approximation interconnected by desmosome-like junctions. CX cells contained cytokeratin, but not vimentin. Elevated levels of squamous cell carcinoma antigen and carcinoembryonic antigen were detected in the cell supernatants. Population doubling time was estimated to be about 20 h. CX cells were not able to grow in soft agar and not tumorigenic in nude mice. Chromosome analysis revealed that CX cells were heterogeneous and mainly had a female diploid karyotype. Unlike cervical cancer cell lines published previously, CX cells were demonstrated to be human papillomavirus-negative, p53 mutation-negative. Based on the distinct characteristics, CX cell line may prove to be a useful tool for the study of human cervical carcinogenesis.