This work focused on characterizing by techniques TGA, DTG and IR, the coagulation of natural rubber latex, by using formic acid and acetic acid, samples classified as clone IAN-710 grown in Caquetá were used, in order to compare the use of these acids on different concentrations, and the impact they have on the thermal and chemical properties (volatile matter and ash). The characterization was carried out by differential scanning calorimetry, thermogravimetric analysis and infrared spectroscopic identification. It was observed that the variation of acids concentration does affect neither the thermal properties within a significant change, nor the major molecular chemical structure of rubber as poly (cis-1, 4 -isoprene).