Shrinking seeds is a form of seeds deterioration in plants. The appearance of shrinking seeds not only influence exterior quality of seeds, but also lower seed vigor and germination ability. At present, shrinking seeds has already become constraints of large-scale of seeds production in hybrid soybean, hybrid wheat and sweat corn.There are some studies on formation mechanism and improvement methods of shrinking seeds, however, it is scatted and lack of systematic summary. The discovery and definition of shrinking seeds, as well as its evaluation methods,influence factor, formation mechanism and improvement methods were summarized in the paper to provide reference to help researchers to understand and resolve this problem.