A novel content-based image retrieval (CBIR) schema with wavelet and color features followed by ant colony optimization (ACO) feature selection has been proposed in this paper. A new feature extraction schema including texture features from wavelet transformation and color features in RGB and HSV domain is proposed as representative feature vector for images in database. Also, appropriate similarity measure for each feature is presented. Retrieving results are so sensitive to image features used in content-based image retrieval. We address this problem with selection of most relevant features among complete feature set by ant colony optimization based feature selection. To evaluate the performance of our proposed CBIR schema, it has been compared with older proposed systems, results show that the precision and recall of our proposed schema are higher than older ones for the majority of image categories