Abstract: Mulberry is a cash crop for alternative planting in contaminated area, and understanding the changes of gene expression of mulberry under heavy metal stress is helpful to explain the physiological phenomena at the molecular biology level. MnMTP1 is selected as the target gene, two mulberry varieties ‘( Xianmianzao’ and ‘Zhehulusang’) with different Cadmium (Cd) absorption abilities are used as experimental materials, RT-PCR technology is used to analyze the relative expression changes of MnMTP1 in the roots of the two varieties. The results of bioinformatics analysis showed that the MnMTP1 had typical structures of CDF family and its homology with other species was 63%-69%. The results of RT-PCR showed that the relative expression level of MnMTP1 gene in mulberry roots changed significantly before and after adding Cd. After water culture with Cd, the MnMTP1 gene was significantly up-regulated in‘Xianmianzao’ and down- regulated in‘Zhehulusang’, which was consistent with the Cd absorption content of the two varieties. The experiment shows that the relative expression level of MnMTP1 gene is related to the Cd absorption ability of mulberry under Cd stress.