1. A content-based image retrieval apparatus via relevance feedback by using fuzzy integral, the apparatus comprising: image input means for receiving images from a user; feature extraction means for extracting image features necessary for image similarity operation from the images inputted via said image input means; first storage means for storing the image features extracted by said feature extraction means; thumb nail generating means for dividing the images inputted via said image input means to generate thumb nails; second storage means for storing the thumb nails generated by said thumb nail generating means; similarity calculation means for calculating the similarities between a selective query image and database images according to feature by using the image features of said first storage means; similarity measuring means for associating the similarities calculated via said similarity calculation means by using fuzzy integral to measure final image similarities; query processing means for interpreting the query from the user to measure similarities, and for sequentially calling and transmitting the images via said second storage means according to the calculated similarities; and user interface means for performing relevance feedback about the image data transmitted from said query processing means, and for transmitting selective information according to relevance feedback to said query processing means.