As an important part of book covers, characters contain rich semantic information. By extracting accurate information from complex color images, and combining it with content-based image retrieval technology, it is possible to further improve the accuracy of book retrieval. According to the characteristics of text information in Chinese book covers, this paper proposes connected components methods to locate the text regions. At first, the grayscale image is decomposed to a series of binary images and merged to connect components in each image, according to the structures of Chinese characters, generating candidate text regions. Additionally, text verification is used to rule out non-text regions. The result regions are regarded as the prominent regions of book cover, further this paper use Hu moment invariant to extract features for image matching. Experiments show the results of this method are fairly good, proving the importance of text information to book retrieval.