A computer readable unified information model is the data foundation in medical imaging semantic retrieve. In this paper, some challenges including lacking of unified information model for medical imaging information, the terminology and syntax for describing the semantic content in medical imaging varying were discussed, and an ontology-based information scheme for medical imaging information integrating was developed. Based on the analysis of medical imaging data source and the relationship of them, a medical imaging information ontology model was developed using "seven-step" method proposed by Stanford University, and the persistence of ontology model, extracting original data and data integration were realized. The information model was used in medical imaging semantic retrieve.