The independent isomeric yield ratios of ^89g,mZr from the ^natZr(γ, xn) reactions and those of ^91g,mMo and ^97g,mNb from the ^natMo(γ, x) reactions with the bremsstrahlung end-point energy of 45– 70MeV were determined by an off-line γ-ray spectrometric technique using the 100MeV electron linac at the Pohang Accelerator Laboratory, Korea. The isomeric yield ratios of ^89g,mZr and ^97g,mNb from the ^natZr(γ, xn) and ^natMo(γ, x) reactions at the bremsstrahlung end-point energy of 16MeV were also determined by the same technique using the 20MeV electron linac at Helmholtz-Zentrum Dresden-Rossendorf, Germany. The measured isomeric yield ratios of ^89g,mZr, ^91g,mMo, and ^97g,mNb were compared with literature data to examine the role of the Giant Dipole Resonance (GDR). The isomeric yield ratios of the ^89g,mZr, ^91g,mMo, and ^97g,mNb from the above reactions were also calculated by using the computer code TALYS 1.6 and compared with the experimental data to examine the validity of the theoretical model for independent isomeric yield ratio calculations.