1. A method for constructing a database to deduce a disease, the method comprising: analyzing U-Health information, which includes a disease, a symptom, and a treatment, and constructing a plurality of U-Health ontologies required for service provision; setting a meta-model defining cause-and-effect relationships between the constructed U-Health ontologies; and selecting at least two specific U-Health ontologies from among the plurality of U-Health ontologies, setting the selected U-Health ontologies as nodes, generating a Bayesian network by applying the meta-model to the set nodes; receiving personal information, and inferring a disease of a user using a probabilistically analysis of said Bayesian network.