Abstract: The present disclosure provides use of miR408 in regulation of cadmium accumulation in crops, and belongs to the technical field of biology. The present disclosure constructs an overexpression vector of MIR408 precursor gene, and transforms MIR408 gain-of-function transgenic rice obtained from a recipient rice, on the one hand can significantly inhibit cadmium accumulation in rice, and on the other hand, have no fundamentally effect on other agronomic traits. Therefore, the present disclosure can provide an important genetic material for breeding low-cadmium rice, and can also be used for genetic transformation of other monocotyledonous crops, providing reference for other crops planted in cadmium-contaminated soil to reduce heavy metal hazards such as cadmium accumulation.