Serialization and deserialization using data contracts. The data contract specifies data types that are serialized and deserialized for data objects that are associated with the data contract. During serialization, the data contract associated with the data object is identified. Then, the data fields that correspond to those specified data field types are extracted from the data object and serialized into a serialization format. During deserialization, the serialization mechanism receives a serialized data structure having a particular serialization format. A data contract is then identified as being associated with the serialized data structure. After deserialization of the serialized data structure into abstract data, a corresponding data object is populated with data fields that correspond only with those data field types specified in the data contract. Accordingly, data abstraction is enabled while serializing and deserializing.