Based on the non-equilibrium Greens method and density functional theory,we investigate the electronic transport properties of teary heterostructures based on carbon nanotubes and boron nitride nanotubes,with different atomic compositions,coupled to gold electrodes.Negative differential resistance (NDR) behavior can be observed due to suppression of the conduction channel at a certain bias.More importantly,the position of NDR can be tuned into the bias range as low as tens of meV by increasing the length of boron nitride nanotube.The peak-to-valley ratio,which is a typical character of NDR behavior,is also sensitive to the atomic compositions.