Aspergillus fumigatus is one of the major sources of cellulases, but its cellulolytic protein expressions on lignocellulosic biomass are still need to be further explored at present.The objective of the research is to identify, quantify and compare the secretome of A.fumigatus that uses corn, wheat or soybean as the sole carbon source, to investigate which genes are transcriptionally modulated for the efficient cellulose degradation and to find the possible enzyme cocktails for its degradation.The result of cellulase enzyme activity produced by A.fumigatus has better pH stability and thermostability.Despite secretion of most of the enzymes on day 2,maximum activity was obtained at day 10 for corn and wheat (CMCase and Xylanase)and day 7 for soybean (CMCase and Pectinase).The result showed the potential activity of Pectinase in all the three carbon source including control (55 U/mg, 120 U/mg, 70 U/mg and 185 U/mg for control, corn, wheat and soybean respectively) followed by Amylase (80 U/mg, 75 U/mg and 80U/mg for corn, wheat and soybean respectively),Xylanase (50 U/mg, 50 U/mg and 83 U/mg for com, wheat and soybean respectively)and CMCase (20 U/mg, 20 U/mg 85 U/mg for corn, wheat and soybean respectively).The difference in enzyme activity among different carbon source is the indicative of compositional and structural variation among them.Moreover, extracellular proteins secreted by A.fumigatus grown on different carbon source were explored using a quantitative proteomic approach with isobaric tags for relative and absolute quantification (iTRAQ).Total of~500 extracellular proteins (88 proteins involved in cellulolysis) were iTRAQ-quantified in presence of all three carbon source, including cellulases, hemicellulases, lignin-degrading enzymes, proteases and some hypothetical proteins.Quantitative iTRAQ results suggested that the expressions and regulations of these lignocellulolytic proteins in the secretome ofA.fumigatus were dependent on both nature and complexity of different lignocellulosic carbon sources.The quantitative mRNA expression of the selected genes were found to be different for 3 different carbon source at different time of incubation which suggest that there is a need of different enzyme combination for different carbon source in order to degrade cellulosic complex more efficiently.