In the context of sustainable development, co-gasification or co-firing of biomass residues and coal is becoming a relevant solution to mitigate the negative impact of fossil fuels. For this reason, it is crucial to understand the characteristics, as well as the thermal behaviors of these residues, especially in a low-oxygen condition that is often found in industrial processes. In this study, woody residues, namely bamboo and rubberwood chips that are abundantly available in Vietnam were characterized. Thermal degradation of these residues in 4 % oxygen was also conducted using a Macro-thermogravimetric analyzer, from room temperature to 700 °C. The results showed that bamboo had a higher volatile matter and a higher hemicellulose content compared to rubberwood chips, hence is easier for ignition in a thermochemical conversion process. Regarding the thermal behaviors of these residues in a reduced-oxygen condition, three stages could be clearly observed in the TGA-DTG curves. Rubberwood chip had a higher ignition temperature and higher temperatures of maximum mass loss rate compared to bamboo chip. Results could contribute to the understanding of the thermal behaviors of these biomass feedstocks in order to improve the efficiency of co-gasification or co-firing processes.