The work aims to study the effect of sugar cane bagasse on its thermal decomposition and kinetics by selecting polymethyl methacrylate (PMMA) to analyze the influence of bio-based materials on thermal degradation of plastic waste. Thermogravimetric analysis of PMMA/bagasse mixtures, prepared in solution blended process, was conducted to study the thermal degradation process under nitrogen atmosphere. Both the maximum weight loss rate method and Ozawa isoconversional method were used to calculate the activation energy and frequency factor of kinetic parameters for PMMA thermal decomposition. The involvement of sugar cane bagasse resulted in significant decrease of the initial thermal decomposition temperature of PMMA, but the thermal decomposition activation energy and frequency factor of PMMA increased remarkably. The calculation results obtained by using the maximum weight loss rate method showed that the activation energy of thermal decomposition after blending sugar cane bagasse into PMMA increased by 26.2 kJ/mol, and the isoconversional method resulted in the activation energy of 168.14 kJ/mol and frequency factor lnA of 28.41 min-1. They were respectively 72.6 kJ/mol and 12.52 min-1 higher than that of pure PMMA accordingly. Blending of sugar cane bagasse has substantially influenced PMMA's thermal decomposition as it makes such decomposition become difficult. Thus it is necessary to further explore the influence of other biomasses on thermal degradation of PMMA.