ABSTRAK
Relative clause (KR) in Arabic Language is an additional constituent describing a nominal head (FN hulu) in sentences. Its location in sentences is always behind the nominal head. Between the nominal head and the relative clause, there is a relative pronoun (PR), which relates both of them. The arrangement is like this: nominal head + relative pronoun + relative clause (FN hulu + PR + KR). In Arabic, relative clause acts like an adjective. There are two reasons that show that relative clause function like an adjective. First, relative pronoun must concord with the nominal head in number, case, and gender. Second, a pronoun that is co-referential with nominal head must appear in the relative clause. In the Arabic language, there are three things have to be concerned. First, the location of the nominal head is always before the relative pronoun and the relative clause. Second, relative pronoun always appears if the nominal head is a definite noun, and disappears after an indefinite nominal head. Third, the relative pronoun man will appear if the nominal head syahsurr `someone' is deleted, and the relative pronoun ma will appear if the nominal head syai'un `something' is deleted.