The Mouse Genome Project has been completed after the Human Genome Project(HGP),but it is only one of the steps for unlocking the mystery of life.The scientists have been working on functional analysis for the genome to seek the rules to health care and overcoming diseases.A number of techniques,such as transgenic animal,gene knockout,large-scale mutagenesis have been applying to functional analysis of genes.But using those techniques,it is even impossible to complete the functional analysis for more than 30000 genes.A new tool,gene trap,has dramatically increased the scientists' ability to finish this tremendous task.In this review,the gene trap technique and information of the related data bank were summarized.