Some genes express only one allelic gene and the another allelic gene is specifically inhibited through some kinds of gene modification. Those genes are called imprinted genes, and they are a unique model of allelic exclusion. Most of imprinted genes participate in regulating development and differentiation of embryo and newborn infant, and disorder of imprinting function may results in many kinds of abnormal development and stilbirth. The mechanisms for the formation of imprinted genes, specific recognization and the defect of imprinting function are still not very clear.