The invention disclosed a method for conducting site-directed modification to a plant genome using non-inheritable materials. The method provided in the present invention specifically comprises the following steps: introducing a non-inheritable material into a cell or a tissue or a part of the plant of interest; wherein said non-inheritable material is a nuclease specific to said target fragment or an mRNA expressing said nuclease, thereby the target fragment is cleaved by said nuclease and site-directed modification to the target fragment is achieved through DNA repairing in the plant. By introducing a non-inheritable material of sequence-specific nuclease, site-directed mutation in a plant gene can be achieved, and no exogenous gene or nucleic acid fragments will be integrated into the plant as obtained. Therefore, the present invention can lead to more precise genome function study and higher biosafety in breeding.