Objective To review the research progress in relationship between hereditary diffuse gastric cancer (HDGC) and CDH1 gene. Methods Literatures on HDGC which were published in recent years were collected and analyzed. Results Aberrant CDH1 gene is significantly correlated with HDGC: mutations of CDH1 exons play the most important role in pathogenesis of HDGC. Screening CDH1 gene mutation is useful for diagnosis of HDGC as well as the treatments. Alterations of CDH1 other than exon mutation, such as intron mutation, gene promoter methylation and single nucleotide polymorphism may result in downregulation of the gene expression. Further study should be done to confirm the roles of these alterations. Conclusions Alterations of CDH1 gene are significantly associated with the pathogenesis of HDGC. Detecting alterations of CDH1 gene are important for diagnosis and management of HDGC as well as to get insights of the pathogenesis of the disease.