The composition of insoluble sediments and adherent gum obtained from ambient and accelerated oxidation stability tests of different cracked middle distillates (LCO, TCO & Coker kerosene) were studied using FTIR Spectroscopy. The sediment & gum formed in these fuels after extraction with methanol were also characterized. The differences in the composition of insoluble sediment & adherent gum obtained under different conditions have been observed.