Empirical tight binding model potentials have been used in molecular dynamics simulations of local order and defects in liquid and glass under high and normal pressures. Results are reported for some solidilike cluster and for structural properties of liquid and glass. Not only are Frank-Kasper polyhedra and Bernal hole polyhedra detected, but also a varity of defective icosahedra. Adramatic split of the second peak of g (r) is associated with the glass transition. The split of the second peak is caused by the fluidity of the liquid phase in glass. The nearest distance is shortened, and the nearest-neighbor corrdination number increase under high pressure. High pressure favors glass formation. The microstructure of glass is very similar to medium range order icosahedra structure.