In this paper, based on the statistical smoothing strategy, a image region feature generative probability estimation method is proposed by exploiting maximum weight matching algorithm. By further analyzing and measuring the semantic correlations between words based on the training set, a novel image annotation algorithm for adopting the generative model is presented. The first annotation keyword is obtained by using the proposed image region feature generative probability estimation algorithm. Then, a heuristic iterate function is proposed to exploit the keyword semantic correlation. Finally, the semantic correlation between the annotation and the image can be improved by our annotation algorithm. The proposed annotation approach is tested on a real-world image database, and promising results are achieved.