Feature-modeling has reached the design mainstream, which was considered as one of ways to integrated system unblocked. Discussing the definition and classification of feature and giving the contents of features of management information, features of technical information and form features, then the part information model was established based on the features in the paper. The systems of treelike part classification coding and feature coding take an important part in the model, which were described based on structural and technological characters of injection parts. Under the rules of feature coding, the feature codes for sprue bush and B plate were developed. The part information model is used to describe, obtain, store, and transmit the part information of the integrated system.