Abstract: In order to theoretically elucidate the relationship between properties and structure of materials, the first-principles method is applied to calculate the electronic states and gain characteristic parameters. Therefore, the structure and properties of materials can be characterized, predicted and designed using these parameters. The authors present the calculated results about lattice constants, bulk moduli, valence charge-density and electronic band structure of Al, Si and BN adopting the first-principles method based on density functional theory(DFT) and pseudopotential, and introduce some of successful applications of these parameters in materials science.