The thermal decomposition of Ag-alg, Se-alg4 and UO2-alg2 compounds has been studied using thermogravimetry (TG), differential thermal analysis (DTA) and electrical conductivity measurements. The original samples are characterized by FTIR spectra. The results obtained reveal that the decomposition of these compounds proceeds via the formation of metal oxalates as intermediate fragments. The electrical conductance of these compounds at low temperature indicates that their geometric structures are non-planar and possess electrical conductivity values which lie in the range of semiconductors. Moreover, the remarkable increase in the conductance values during the decomposition of the intermediate metal oxalates is attributed to the hopping mechanism between the different valencies which exist during their thermolysis. Finally, detailed mechanisms of the various decomposition stages of the metal alginate compounds are suggested.