In this paper, we combine WSMO with ebXML and move the distributed choreography in a cloud environment to form semantic business collaboration architecture. We employ the information model and service interfaces from ebXML Registry and Repository to design the knowledge portal of the architecture which stores the domain ontology, collaboration protocols, collaboration protocol profile of partners, etc. We investigate two cases to apply the use of the semantic business collaboration on the cloud: one is to develop the choreography of electronic official documents and the other is to design the portal service for government open data.