We study the phase behavior of self-assembling grafted comblike copolymers with strongly attractive side chains. An off-lattice, microscopic integral equation theory is applied to investigate intermolecular correlations, collective scattering intensities, and thermally induced macro- and microphase separation transitions in the systems of different comb models having various architectures and chain stiffness. The properties of these models are analyzed as a function of molecular density, the number of side chains, the length of the side chains and backbone. Detailed calculations reveal the main factors that control micro- versus macrophase separation and thereby yield guideline for controlling the phase behavior of comblike copolymer systems in solutions and in melts. (C) 2000 American Institute of Physics. [S0021-9606(00)51207-0].