The application of numerical transmission matrix calculation was repor
ted to solve the bound and quasi-bound states in arbitrary potential o
f one-dimensional system. Through a numerical decomposition for the 2x
2 matrix multiplication, this method can be used for the heterostructu
re system with the size of normal device. The subband characterization
of two kinds of superlattice with the size of the normal device was a
nalyzed by this method.