This study explores generational differences in preference and judgement factors to the styles of popular illustrations by means of interview survey, content analysis and statistical test. A total of 180 subjects were recruited from the Taipei area, evenly divided between adolescents and adults, as well as males and females. The results showed significant differences of preference and judgement factors between generations and the same as in different illustration styles; cognitive assessment is the most important factor of preference judgement. In addition, the preference judgement factors of adults are not corresponding to the progress of cognitive development in that they are not moving forward to more advanced stages, but backward to those of subjective and emotional judgments of children. This phenomenon may be caused from the fact of generational differences in adepting to the visual cultural environment, but still needs to be confirmed in the future studies.