Abstract: A molecular marker of cadmium accumulation in rice improves cadmium accumulation in rice grains. The molecular marker of cadmium accumulation in rice includes a DNA fragment shown in the 8899129-9307609 region of rice chromosome 7, which is lcrf1 or lcrf2, lcrf1 is a DNA fragment shown in the 8899129-9307609 of rice chromosome 7, and the lcrf2 is the DNA fragment shown in SEQ ID No.1 in the sequence listing. The present invention finds that the molecular marker of cadmium accumulation in rice is related to the cadmium accumulation in rice grains, and the homozygous rice whose molecular marker of cadmium accumulation in rice is SEQ ID No. 1 in the sequence listing has the characteristics of low grain cadmium accumulation when planted in high cadmium polluted fields. Therefore, the DNA fragment can be introduced into other backgrounds by breeding methods such as hybridization and backcrossing.