Various effects of the pion-pion interaction on the photonuclear reactions through the phenomenological r-3ninteraction 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.In Part I the main results are summarized in Figures and Tables in order to make facile to compare with experiments. Readers who want to know only the results may skip over Parts II and III. In Part II the effective ')'-3·7t Hamiltonian is given, and appropriate approximation is made for the I =J = 1 pion-pion resonance in the matrix elements of photoprocesses. These approximations often lead us to overestimation of the effects, as is criticized in the last part of Part II. In Part III calculations of various processes are given in detail.