Knowledge Provenance is an approach to determining the origin and validity of knowledge/information on the web by means of modeling and maintaining information sources and dependencies, as well as trust structures. This paper constructs an uncertainty-oriented Knowledge Provenance model to address the provenance problem with uncertain truth values and uncertain trust relationships by using information theory and probability theory. This proposed model could be used for both people and web applications to determine the validity of web information in a world where information is uncertain.