Methods for Production of Medical Radioisotope ⁹⁹Mo

^99mTc, as the decay daughter of ⁹⁹Mo, is the most frequently used radionuclide in nuclear medicine. The usage of ⁹⁹Mo is not less than 70% of that of the all radioisotopes. The methods for ⁹⁹Mo production by nuclear reactors, accelerators and neutron generators were studied. Here, based on the investigated literatures, methods for ⁹⁹Mo production had been analyzed with an emphasis on ⁹⁹Mo production extracted from ²³⁵U fission products with high enriched uranium (HEU) or low enriched uranium (LEU) target. Due to the recently rapid development of methods for ⁹⁹Mo production by accelerators and neutron generators, the achieved progresses were reviewed in this respect. In the present paper, some advices were also given for further exploration.