3R-TaSe2 nanobelt quasi-arrays were gown on a Ta foil by a facile two-step method, namely, firstly the TaSe3 nanobelt arrays were grown on a Ta foil by a surface-assisted chemical vapor transport, and then they were pyrolyzed to 3R-TaSe2 nanobelt quasi-arrays in vacuum. The nanobelts have low work function and the Ta foil has high conductivity, so the nanobelt arrays possess good electronic field emission performance with a low turn-on (3.6 V/microm) and threshold fields (4.3 V/microm) (which are defined as the macroscopic field required to produce a current density of 10 microA/cm2 and 1 mA/cm2, respectively) and a high enhancement factor (1045) at an emission distance of 200 microm. The electric transport of the individual nanobelt reveals that it is a high-conductive semiconductor, and observed by the variable-range hopping model. It suggests that the nanobelts have potential applications in field emission and field effect transistors.