In this paper we present a storage method for sets of first order logic terms in a relational database using function symbols based indexing method of Discrimination trees. This is an alternative method to a published one, based on attribute indexing. This storage enables effective implementation of several retrieval operations: unification, generalization, instantation and variation of a given query term in the language of first order predicate calculus. In our solution each term has unique occurrence in the database. This is very useful when we need to store a large set of terms that have identical many subterms. Key words: first order logic terms, relational database storage and retrieval, first order logic term indexing