Time-resolved transient absorption spectra of neat liquid cyclohexane-h12, cyclohexane-d12, n-hexane, trans-decalin and isooctane were measured by means of picosecond 266 nm multiphoton laser photolysis. In each case, broad transient absorption spectra assigned to the S1 → higher excited states transition were obtained. On the basis of the profiles of the transient absorbance, the excited state formation process as a consequence of ionization followed by recombination and the photodecomposition process were elucidated.