We have investigated the electronic and structural properties of pristine Zinc-blende type InP nanowires (NWs) by using ab-initio approach. We have considered the effect of phases by taking NWs of 7 Å radii in three phases viz. (100), (110), (111). It is revealed that the electronic properties of NWs are highly affected by the wire phases. NW in (100) phase is found to be semiconducting with an indirect band gap of 0.71 eV whereas it becomes semi-metallic and metallic in other two phases. Thus, the nature of nanowires is observed as a function of NW phases. Further, energetic feasibility of InP NWs strongly dependent on their growth phase.