Effective monopole action at finite temperature in SU(2) gluodynamics is studied on anisotropic lattices. Using an inverse Monte-Carlo method and the blockspin transformation for space directions, we determine 4-dimensional effective monopole action at finite temperature. We get an almost perfect action in the continuum limit under the assumption that the action is composed of two-point interactions alone. It depends on a physical scale b_s and the temperature T. The temperature-dependence

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... rs with respect to the spacelike monopole couplings in the deconfinement phase, whereas the timelike monopole couplings do not show any appreciable temperature-dependence. The dimensional reduction of the 4-dimensional SU(2) gluodynamics ((SU(2))_4D) at high temperature is the 3-dimensional Georgi-Glashow model ((GG)_3D). The latter is studied at the parameter region obtained from the dimensional red uction. We compare the effective instanton action of (GG)_3D with the timelike monopole action obtained from (SU(2))_4D. We find that both agree very well for T > 2.4T_c at large b region. The dimensional reduction works well also for the effective action.