Hadronic structure in QCD has been analyzed by using the Fock state wavefunctions of hadrons defined by quantizing quantum chromodynamics at equal time of the light-cone. They provide a unified approach to QCD phenomenology. We have presented a convenient method for operator product expansion in the external background fields and have obtained the distribution amplitude moments values from QCD sum rule by introducing the condensate effect of quarks and gluons. These results are in agreement with the present data.