The electron resonant tunneling in a T-stub low-dimensional conductor was studied in terms of the lattice Green’s function method. The numerical calculations show that the electrons can pass through the conductor for some Fermi levels. With the increase of the Fermi energy, more and more transport model take apart in the tunneling, and then the transmission increase from 1 to 2, 3 and so on. The numerical calculation results will be helpful for quantum device design.