This paper examines Fernand Khnopff’s Symbolism, focusing on the I Lock My Door upon Myself as a manifesto of his artistic credo in style and theme. Its title was originally in English, originating from the poem “Who Shall Deliver Me?” by Dante Gabriel Rossetti’s sister Christina Rossetti. I use the term “Social Symbolism” which combines a nationalist perspective with traditional French Symbolism, in order to explain how the image of Bruges is represented in his oeuvre. Symbolism calls for psychological introspection evoking death, love, silence, and solitude and recluse from realty in pursuit of the Unknown and the Ideal. Although Khnopff shared this idea, he departed from symbolist tradition by incorporating a political milieu in his paintings. First, I discuss Khnopff’s early stage in the formation of his artistic concept, including his family background as well as his early opportunity to visit the Exposition Universelle in Paris where he formed his early interests in aesthetics, philosophy, literature, mythology and Egyptian art. His early works, La Painture, la Musique, la Poesie(1880-1881), Le Crise(1881), and En ecoutant Schuman(1883) reveal his favorite subjects which were quite prevalent in the symbolist traditions of both Belgium and France. By looking at Khnopff’s paintings, I endeavor to situate his Symbolism in the context of the development of Belgian modernity and cultural nationalism. Second, my analysis of Khnopff creates a new overview of Symbolism in Europe, especially in Belgium. In the absence of socio-political integration, the Symbolist painter adds nostalgic meaning to the landscape of Bruges. The scene of Bruges illuminates the social atmosphere in Belgium at that time. Since Belgium became an independent country, it tried to differentiate its own cultural and national identity from France. There was a powerful social movement for Belgium to claim its own identity, language, and culture. Bruges was, for Symbolists, the epitome of Belgium’s past glory. This encouraged the formation of Belgian nationalism centering on Brussels, as I demonstrate in Khnopff’s Bruges-la-Morte(1892). The relationship between Symbolist artist and writers is crucial for understanding this development. Khnopff, for instance, illustrated or provided frontispieces for many Symbolist writers such as Rodenbach, Peladan, Spencer and Le Roy. Khnopff did not objectify the exact meaning, but rather provided his own subjective interpretation. In this respect, I Lock My Door, inspired by Rossetti, started from the same motif, but Khnopff seeked escape into silence and death while Rossetti searched for Christian salvation. Finally my paper deals with the social context in which Khnopff worked. He was a founding member of Les XX in 1883 and later La Libre Esthethetique he also participated in the exhibition of le Salon de la Rose + Croix. Les XX was not a particular school of art and did not have a uniform manifesto, but its exhibitions focused on decorative arts by encompassing art for all people via common, everyday objects. The Periodical, L’art moderne was founded to support this ideal by Edmond Picard and Maux. Les XX declared art as independent art, detached from all official connections. Khnopff designed the 1890 catalogue cover of Les XX and the 1891 cover. These designs show decorative element of Art Nouveau in an early example of “modern poster.” Les XX pursued all art including graphic arts, prints, placard, posters and book illustrations and design. These forms of art were l’art social and this movement was formed by the social atmosphere in Belgium in terms of social reforms and strikes by working class. Khnopff designed the book cover for la Maison du Peuple. The artist, however, did not share the ideal egalitarianism of the working class to a certain degree, while he was working in his villa he designed under the ideal motto, “on n’a pas que,” he expressed the nihilistic emotions toward society by the theme of interiority such as solitude, silence, narcissism, introspection, and introversion. In the middle of his Symbolism, we find the “cultural nostalgia” or longing that the artist develops in the I Lock My Door upon Myself. Khnopff’s longing toward the lost city of “Bruges” form the crux of his “Social Symbolism.”