Biomethanisation process of rubber seed cake and cow dung were influenced by the effect of catalyst, temperature and acetic acid. TiO 2 catalyst was used for the study. The maximum biogas yield was obtained from the substrate mixed with 2% TiO2 at 40°C with constant stirring but the yield obtained was very insignificant in the absence of catalyst at all the temperatures. The optimum temperature for biomethanisation was 40°C. Further the high biogas yield increase with methane composition of 32% for mixture at 18°C by the addition of small amount of acetic acid and volatile fatty acid at cold condition. The obtained gas was analysed using gas chromatography (GC). The first order kinetic model was applied to the substrate that produced the maximum yield and the theoretical values were obtained from the equation fitted with experimental values.