[en] Integral solution enthalpies of lithium perchlorate in diethyl ether, acetonitrile, acetone and DMSO at 298,2 K are determined calorimetrically; they are equal to -6.2, -9.1, -15.9 and -18.0 kcal/mol correspondingly. For diethyl ether dependence of integral solution enthalpy on salt concentration within the range from 3 x 10^-3 up to 5,6 mol/l is determined. Reducing exoeffect of salt dissolution in the ether from -6 up to -5 kcal/mol in the range of small concentrations (3 x 10^-3 - 3 x 10^-2 mol/l), the constancy of the effect in the 5 x 10^-2 - 1.3 mol/l range and following smooth reducing exoeffect up to -3.2 kcal/mol at salt concentration 5.6 mol/l is pointed out