In this study, we tried to find out whether the socio-cultural thinking styles of individualism and collectivism could affect the basic visual perceptual processes such as Müller-Lyer(ML) Illusion. If the collectivistic thinking style induces people to perceive the illusory figure more holistically and to process the relations among the components, collectivism-primed people are more susceptive to the ML illusion. On the other hand, if the individualistic thinking style induces them to perceive the illusory figure more analytically and to process the components separately, individualism-primed people are less susceptive to the illusion. To study the influence of cultural thinking styles on perceptual illusion, one group of Korean students wrote a story about “myself” for individualism priming and the other group about “our group” for collectivism priming before the illusion task. As expected, the individualism-primed group showed less ML illusion effect than the collectivism-primed group. In summary, this study suggested that cultural thinking styles could affect the basic visual perceptual processes in a top-down way.