Abstract: In the present paper, the ground and several low-lying excited states of H₃⁺ were discussed by using the bonded tableau approach for valence bond theory, and the features of valence bond structures of H₃⁺ were studied.It has been obtained that the geometries of H₃⁺ at the ground and the first excited states are equilateral triangular and linear, respectively, For the ground state, the bond length is 0.08752 nm, which is in agreement with previous results.The first excited state is a bound state and can be described by three resonance structures.The second and the third excited states prefer isosceles triangular and are near-degenerate, however they are not stable states and are the products of the very weak interaction between H₂⁺ and H.

Key words: H₃⁺, Excited states, Valence bond approach