Abstract: The transition metal chalcogenide nanostructures of NiSe and CoSe in different states namely cationic, anionic and neutral are completely simulated and optimized successfully by B3LYP/LanL2DZ basis set. Stability of transition metal chalcogenide structures has been conversed by using calculated energy and vibrational studies. Electronic properties of NiSe and CoSe are studied in terms of HOMO-LUMO gap, electron affinity and ionization potential. The point symmetry and dipole moment of NiSe and CoSe are also reported. This study is concentrated in enhancing electronic properties of transition metal chalcogenide which is most applicable to solar cells, lithium ion batteries and as catalyst.