Measurements of neutron total cross sections of natural bismuth in the neutron energy region from 0.1 to 100 eV have been performed by using the time-of-flight method at the Pohang Neutron Facilitywhich consists of an electron linear accelerator, a water-cooled tantalum target with a water moderator,and a 12 m long time-of-flight path. A 6Li-ZnS(Ag) scintillator with a diameter of 12.5 cm and a thicknessof 1.6 cm is employed as a neutron detector, and a piece of high purity natural bismuth metallic plates with a thickness of 3 mm is used for the neutron transmission measurement. The present results were compared with the evaluated data from ENDF/B VII.1 and other previous reported experimental data.