Pulse radiolysis of solutions of 10-methylanthralin and 10, 10-dimethylanthralin under various conditions including air saturated benzene, O 2 saturated benzene and with sodium azide in N 2 O saturated acetonitrile: phosphate buffer (pH=7) were investigated, respectively. 10, 10-Dimethylanthralin triplet observed in all cases and found to decay with first order kinetics (K = 4. 96 E+06 sec-1 , K = 1.53 E+07 sec-1). As expected, only 10methylanthralin free radicals were formed at wavelengths of 400-760 nm. Also, pulse radiolysis of 1,8-Dihydroxy-9-anthrone (Anthralin) solutions at concentration of 1 10-4 M with sodium azide (NaN 3) (1 10-2 M) in N 2 O saturated CH 3 CN: Phosphate buffer (1:1 v/v) (pH7) was investigated and the corresponding free radical observed at wavelength of 720 nm.