Provided is a system and method for creating and providing a mosaic image based on an image tag-word by a mosaic service providing server, which includes: determining each tag-word for each image and classifying a plurality of images according to the determined tag-word; determining a target image among the plurality of images; providing a pixel image selection interface for selecting a pixel image for mosaicizing the determined target image based on the tag-words of the plurality of images; and creating a mosaic image for the target image based on the pixel image selected through the pixel image selection interface.