The aim of this paper is to investigate the syntactic structure of the so-called transparent relative clause. What in the standard free relative clause has been treated as a unit including a head NP and a relative pronoun together. In the case of transparent free relatives, however, a what-clause reveals some peculiar characteristics different from standard relative clauses. To explain those characteristics, many linguists have suggested several different analyses. The analyses can be categorized into three groups: Backward Deletion, Shared Structure analysis, (Rightward) Movement and Deletion analysis. Because of their drawbacks, I have suggested Leftward Movement and Deletion analysis, and adopted Winkler's(2005) D(rivational)-Model of Grammar to explain the interactions between the PF deletion and LF interpretation.