Methods, systems, and apparatus, including computer programs encoded on computer storage media, for data tracing are provided. One of the methods includes: receiving a data backtracking request, the data backtracking request comprising a version identifier of a first data version of a target object; obtaining, from the blockchain, version identifiers of a plurality of second data versions of the target object and a plurality of data blocks in the blockchain, wherein the second data versions comprise an initial data version of the target object, and at least one of the obtained data blocks comprises a version identifier of the initial data version; and determining, based on the version identifier of the initial data version, data content corresponding to the initial data version of the target object.