When recognizing three-dimensional (3-D) objects, interobject similarity and stimulus density affect sensitivity to spatial frequencies (Kondo & Toshima, 2000). However, it has not examined whether effect of interobject similarity and stimulus density available under the condition of 3-D object recognition only or not. We investigated this question by carrying out an experiment that was removed view factor from Kondo & Toshima (2000). From the result, there was no interaction among factors of interobject similarity, stimulus density and spatial frequency, it suggest that interobject similarity and stimulus density do not affect spatial frequency under the condition of two-dimensional object recognition.