The purpose of this study is to compare and analyze the unconscious principles of expression and the formative language through comparison between Salvador Dali and Rene Magritte. The surrealist painter Dali and Magritte based on unconscious expression, repeatedly portrayed images of repressed unconsciousness in childhood. This study compared these unconscious expressions by characteristics of style and subject of works and related with their attitude to life. The result of this study is as follows. First, there is a difference between Dali having the gumption with aggressive expressions in works and Magritte expressing unconsciousness in a negative and contemplative manner after thematically examining the contents of their main works. Secondly, there is a difference between their formative languages such as color, composition, form, and space. Dali shows the dynamic composition, the saturated colors, the curved lines, and he only strictly uses close-range view and distant view. Otherwise Magritte shows static composition, depressed and cold colors, straight lines, and he uses near, medium and distant landscapes all in spatial expression. Third, this study confirmed a difference between them on their attitude to life. While Dali shows self-loving remarks and attitudes to show off his value and ability, Magritte pursues anonymity by showing an attitude related to depression.