Effective α-α potential is investigated from the standpoint of the cluster model by making use of reliable properties of the pion-theoretical nucleon-nucleon potentials. The main features of α-α potential (outside attraction, inside repulsion and angular momentum dependence) demanded from the analyses of low energy α-α scattering phenomena can be qualitatively reproduced. In constructing the α-α potential, the importance of the Pauli principle should be emphasized, which damps the relative wave function of two α-particles at small α-α distances. Its connection with nucleon-nucleon potentials is also discussed.