. Degradation of organic matter from peat soil produces various phenolic acids, CO2, and CH4. The phenolic acid is known toxic and causes plant growth retardation. Some of pesticide is unintentionally drip on peat soil surface and reacts with organic matter. This study was aimed at evaluating the influence of pesticides on phenolic acid bondings as well as CO2, and CH4 emissions. Two types of pesticides were used: herbicide paraquate dichloride and insecticide Buthylphenylmethyl-carbamate (BPMC). The pesticide dosages were based on the recommended application, i.e. 4 liter ha-1 for paraquat and 1 liter ha-1 for BPMC. Treatments were consisted of 3 levels of dosage (half, equal and two-fold the recommended rates: μg kg-1): 1,104; 2,208; and 4,416 for paraquat and 485, 970, and 1,940 for BPMC and a control treatment. After 1, 7, 14, and 28 days of incubation, soils in each treatment were analyzed for phenolic acids, pesticide residues, functional groups, and CO2 and CH4 emissions. The results showed that pesticide application reduced the total phenolic acid concentrations of peat soil. Paraquat and BPMC applications showed a similar pattern on soil phenolic acid concentrations. BPMC dosage of 485 μg kg-1 reduced 95% of pesticide residues, which was the highest reduction compared to any other dosages. In general, paraquat application at the tested dosages left no pesticide residues after 28 days of incubation. The FTIR analysis did not detect appearance of any new functional groups under the tested rates and types of pesticides. However, altered intensity of the absorption peaks could be an indication of compositional changes of the chemical substances within peat soil during the incubation period. Pesticide application did not significantly affect CO2 and CH4 emissions.