Abstract: Objective To screen the exon12 mutation of pot1 gene in cultured human carcinoma cell strains (lines). Methods The chromosomal DNA was extracted from 27 cultured carcinoma cell strains (lines). The exon 12 of pot1 gene was amplified by PCR, and the product was purified and screened. The screening results were compared with the data of GenBank and NCBI and the exon 12 mutations in cultured human carcinoma cell strains (lines) analyzed. Results The exon12 sequence of pot1 could be specifically amplified using the designed primers. Direct sequence analysis of the PCR products after purification showed that 4 of the 5 carcinoma cell lines of the female genital system such as Hela and HO8910-PM cells shared the same transition (G17722→C) in exon12 of human pot1 gene resulting in a conversion of G1385→C in the cDNA and amino acid change of Leu454→Phe in the translated polypeptide. The rest of the 23 cell strains (lines) from different origins showed no such mutation. Conclusion The exon12 (17 722 bp) is a mutant region specific for female genital system tumor.