We give the equivalence between pre T _½ space and some types of mappings. The aim of this paper is to discuss and investigate some characterizations for pre T _½  spaces. Also, the implication of this notion among themselves and with the well-known axioms such as : pre-T₀, pre-T₁ and pre-T₂ are introduced.   Furthermore we introduce and study the definition of preT_D and pre-symmetric spaces and some of their properties are discussed.