With the ultraviolet-visible spectrophotometry and electronic structure calculations, we have investigated the effects of photo-irradiation on the optical properties and electronic structures of an azo-containing banana-shaped liquid crystal. The synthesized compound exhibits two optical absorptions at about 275 and 360nm, respectively. Our electronic structure calculations reveal that the two absorptions can be attributed to the sigma* and * transitions in the azo-chromophores of the banana-shaped liquid crystal. Our results have demonstrated that photo-dissociation takes place predominantly when dilute tetrahydrofuran solution of the azo-containing liquid crystal is exposed to the 365nm irradiation despite tran-to-cis photochemical isomerization is observed.