Abstract: Hybridization and polyploidy may trigger changes in genome structure and cause widespread alterations in gene expression.Thus,hybridization and succedent polyploidy is a prominent and significant process in plant evolution.Many studies have demonstrated that the complicated changes in gene expression always occurred after polyploidization,including gene silencing,genomic bias and tissue-specific expression of some genes,and gene activation,etc.In this review,we summarized the characteristics of the changes of gene expression in polyploid plants and their molecular mechanisms.