Generation of the radical cation from 1B(u)-type states (1B(u)(+) and/or 1B(u)(-)) of all-trans-beta -carotene in chloroform was demonstrated by sub-picosecond time-resolved absorption spectroscopy. In the visible region, ground-state absorption bleaching completely recovered in n-hexane but not in chloroform. In near-infrared, broad transient absorptions from 1B(u)(+) and 1B(u)(+) states appeared and decayed within I ps in both solvents, while weak transient absorption ascribable to the cation appeared and stayed until 40 ps after excitation in chloroform, but not in n-hexane. In chloroform, direct transformation from the 1B(u)-type singlet state to the radical cation had a time constant 0.14 +/- 0.03 ps.