The low-temperature heat capacity C p,m of 2-methyl-2-butanol was precisely measured in the temperature range from 80 to 305 K by means of a small sample automated adiabatic calorimeter. Three solid-solid phase transitions and one solid-liquid phase transition were found at TοΌ146. 355, 149.929, 214.395 and 262.706 K from the experimental C p -T curve, respectively. The dependence of heat capacity on temperature was fitted to the following polynomial equations with a least square method. In the temperature range of 80 to 140 K, C p,m οΌ39.208οΌ8.0724X-1.9583X 2 οΌ10.06X 3 οΌ1.799X 4 -7.2778X 5 οΌ1.4919X 6 , XοΌ(T-110)/30; in the temperature range of 155 to 210 K, C p,m οΌ70.701οΌ10.631XοΌ12.767X 2 οΌ0.3583X 3 -22.272X 4 -0.417X 5 οΌ12.055X 6 , XοΌ(T-182.5)/27.5; in the temperature range of 220 to 250 K, C p,m οΌ99.176οΌ7.7199X-26.138X 2 οΌ28.949X 3 οΌ0.7599X 4 -25.823X 5 οΌ21.131X 6 , XοΌ(T-235)/15; and in the temperature range of 270 to 305 K, C p,m οΌ121.73οΌ16.53X-1.0732X 2 -34.937X 3 -19.865X 4 οΌ24.324X 5 οΌ18.544X 6 , XοΌ(T-287.5)/17.5. The molar enthalpies of these transitions were determined to be 0.9392, 1.541, 0.6646 and 2.239 kJβ’mol -1 , respectively. The molar entropies of these transitions were determined to be 6.417, 10.28, 3.100 and 8.527 J H 298.15 ] and [S T -S 298.15 ], were derived from the heat capacity data in the temperature range of 80 to 305 K with an interval of 5 K.