Background: Essential genes are indispensable for the survival of organisms.Up to now,those important elements have been screened in more than forty bacteria by wet-lab methods.It provides a chance to perform theoretical analysis.Prediction is a hot spot among them,and it gives an alternative way for essential genes identification.Now there are mainly four computational methods: (1) Homologous alignment based methods (2) Sequence features based methods (3) Network topological based features (4) Integrated method combined with the three mentioned above.