Abstract: Abstract: Expression of abnormal open reading frame formed by mitochondrion gene recombination plays a very important role in the plant cytoplasmic male sterility. In this study, carrot mitochondrion gene fragments atp8 associated with cytoplasmic male sterility were isolated and cloned. Compared with sterile line, maintainer line atp8 gene has a lot of mutations between 30 bp and 170 bp, and the sequence between 154 bp and 162 bp was missed. Blast analysis indicated that maintainer line atp8 gene shares an identity of 100% with carrot nad6 gene. The expression analysis using semi-quantitative RT-PCR and Real-time PCR demonstrates that expression of atp8 gene in carrot sterile line is significantly lower than in maintainer line besides the flowering stage. These researchers indicated that abnormal expression of atp8 gene has a close relationship with carrot cytoplasmic male sterility.