This study aims to evaluate influence of firing on soil properties at Zone A5, Tram Chim National Park, Tam Nong district, Dong Thap province. The findings indicated that the soil type was acid sulfate, the soil structures were clay, clay-silt and silt-clay. The pH was low while moisture was high. Electrical conductivity and bulk density were in the tolerance range for Eleocharis community. The soil was rich in nitrogen, phosphorus, and organic matters while it was medium in total potassium. After firing, clay tended to decrease while sand and silt slightly increase. Moisture, pH, electrical conductivity, total phosphorus and potassium increased whereas organic matters and nitrogen content tended to decrease. Bulk densities were almost unchanged over times.  This study preliminary provides important information on the changes of soil properties under firing.