A new classification of large solar flares is presented. If the time spacings between the flares are over 2.5 days, the flares and the corresponding interplanetary streams are classified as isolated ones. The concepts of the nearest, intermediate and distant flare zones (N, I and D zones) are introduced. The limits of the zones are determined at 30° longitude intervals and at 15° latitude ones. The classification is applied to the flares of 1966-1974 (Ivanov et al., 1979). It allows one to study the interplanetary and the magnetospherical disturbances more systematically.