Photoamination of 1,2-distyrylbenzene (1a) with NH3 in the presence of p-dicyanobenzene has been investigated. 1-Benzyl-3-phenyl-1,2,3,4-tetrahydroisoquinoline (2a) and 1-amino-3-benzyl-2-phenylindan (3a) were formed as a consequence of the nucluophilic additions of NH3 to 1a+· and indan-type cation radical (4+·) generated by transformation of 1a+·.