Direct reference theory, against Frege's and Russell's view, claims that the semantic content of a proper name does not have any description as its sense and that name without any attributive means, i.e. directly, designates its referent, viz., the semantic content of a proper name is its referent. Empty proper names create some problems in this theory: Does the sentence which contains such names express any proposition? And can it be believed? Does this kind of sentence have truth values? What about the justification of true negative existential sentences? And, finally, if these sentences lack any semantic content how could their obvious difference in meaning be justified? In this article, I will do a critical investigation of the most important answers to those problems, and will show that, though some of these answers are valuable, they are not complete.