The authors present the results concerning the synthesis and the characterisation of some coordination compounds with malic acid as ligand: Co(C4H4O5). 2H(2)O, [Fe-2(C4H4O5)(OH)(4)]. 4H(2)O and [Fe2Co(C4H4O5)(2)(OH)(4)]. 6H(2)O The heterometallic compound is a precursor of Co-ferrite. The values of the non-isothermal kinetic parameters for the dehydration reactions were determined. These values obtained by three integrals methods are in a satisfactory agreement.