DPOAEs are acoustic phenomena which are considered to be generated by the activity (excitation force) of the outer hair cells (OHCs) when the cochlea is stimulated by a complex tone consisting of two tones. Levels of the distortion components are generally considered to be correlated with the hearing level. However, the relationship between the generated distortion components and the excitation force of the OHC at each part of the basilar membrane (BM) has not yet been clarified. In this study, the relationship was investigated using finite-element human cochlear models having non-active portions of the BM. A complex tone (f1 and f2) was applied to the head of the stapes, and distortion components of 2f1-f2 on the stapes and at each point of the BM were calculated. The level of the distortion components was lower than that of the normal cochlea when non-active portions were introduced at the more basal region from the characteristic frequency (CF) point of f2. This result suggests that the activity of the OHCs at the more basal part from the CF point of f2 plays critical roles in the generation DPOAEs.