This thesis is based on experimental studies carried out with an opposed-flow, diffusion flame to investigate (i) the effect of fatty acid methyl ester (FAME) molecular structure on flame structure and (ii) the accuracy of existing detailed chemical kinetic mechanism of methyl butanoate, a surrogate of bio-diesel.The experiments involve measurement of species concentration and temperature due to combustion of methyl butanoate in an opposed-flow diffusion flame. Studies have also been performed on the flame structure of methyl crotonate, an ester of 2-butenoic acid, in order to observe the effect of the double bond on the chemical kinetics of methyl crotonate and, in general, larger unsaturated bio-diesel molecules.The analysis of the flame samples was performed using a Gas Chromatograph and an NDIR analyzer.