局部态密度(Local density of states) (LDOS)是指在实空间分布的态密度。它可以通过扫描隧道显微镜得到，也可以在已知晶体结构和材料特性的情况下，通过计算机仿真得到，比如密度泛函理论。

LDOS可以用来分析器件具体工作原理。比如，右图是一个金属氧化物半导体场效应晶体管(MOSFET)中的LDOS随着晶体管开通和关闭的变化，该图通过计算机仿真得到。源极和漏极中清晰可见导带和禁带的分界线，以及束缚能级。在中间的沟道，随着栅极电压增加，势垒高度下降，密度增加，晶体管开通。

Local density of states (LDOS) is a physical quantity that describes the density of states, but space-resolved. In materials science, this term is useful when interpreting the data from an STM, since this method is capable of imaging electron densities of states with atomic resolution. According to crystal's structure, this quantity can be predicted by computational methods, as for example with density functional theory.