Abstract: Automatic image annotation is the process of assigning keywords to digital images depending on the content information. Automatically assigning keywords to images is of great interest as it allows one to index, retrieve, and understand large collections of image data. Selection & implementation of proper feature extraction and weight calculation method plays important role in image annotation. Many techniques have been proposed for image annotation in the last decade that gives reasonable performance on standard datasets. This paper presents detailed literature about the Automatic Image Annotation and explains the feature extraction as well as weight calculation method.