Photo-cross-linkable side-chain liquid crystalline copolymers comprising a photoreactive 4-(2-cinnamoylethoxy)biphenyl side group and a photoinactive 4-cyanobiphenyl group were synthesized, and thin films of them were irradiated by linearly polarized (LP)-UV light, inducing an alignment of both mesogenic groups with the direction parallel to the electric vector (E) of the incident LP-UV light. The effects of copolymer composition and irradiation temperature on the photoinduced alignment behavior have been investigated in detail. For nematic copolymers, an induced anisotropy increased with increasing the LP-UV irradiation temperature and decreased above the clearing temperature (Ti) of the film. On the other hand, for smectic copolymer films, the photoinduced alignment was only observed when they were exposed at the temperature just around Ti. For the smectic copolymers irradiated in their smectic temperature range, intramolecular photoreaction was the major reaction. In contrast, intermolecular photoreaction became the major reaction around Ti as well as the nematic copolymers since the mobility of the mesogenic group became large. We conclude that the intermolecular photo-cross-linked mesogenic group can control the alignment of nonphotoreacted and photoinactive mesogenic groups along to the E direction, whereas the intramolecular photoreacted group cannot control the alignment of the other mesogenic groups.