[en] Experiments on the ohmic heating and compression of a plasma on the ''Tuman-2'' toroidal facility have been carried out. While ohmic heating in a toroidal field of 3-5 koe, a plasma of density μ 10¹³ cm^-3 and electron temperature 20-30 eV has been obtained. With an increase in toroidal field from 3.2 to 11.5 kOe within 125 μs, an effective compression of the plasma filament has been observed. The plasma density increases by a factor of three, and the electron temperature, by a factor of 2.5. It has been established that compression heating is due to the improvement of a plasma thermal insulation. At the same time, a decrease in plasma oscillations and weakeninq of the filament-diaphragm interaction is observed. Measurements of the density radial distribution have shown that compression considerably reduces the transverse diffusion rate. For a compressed filament the diffusion coefficient D(<=)2x10³ cm²/s, which is less than 0.1 of Bohm's diffusion coefficient and is in accordance with the coefficient given by the pseudoclassical theory