Various effects of the pion-pion interaction on the photonuclear reactions through the phenomenological γ-3 π interaction are investigated. Processes discussed here are pion photoproduction, double pion photoproduction, and electromagnetic properties of the deuteron. The following problems are investigated in detail: (i) angular distribution, (ii) polarization of the recoil proton, (iii) photopion with polarized gamma rays, for neutral pion photoproduction; and (iv) plus-minus ratio of charged pion photoproduction, (v) double pion photoproduction. For the electromagnetic properties of the deuteron, (vi) magnetic moment, (vii) electric quadrupole moment, and (viii) photodisintegration are studied.