The self-assembly structures and their transformation of blends of rod-coil-rod triblock copolymers and homopolymers were first detected. Adding coil homopolymers into block copolymers with a lamellar structure resulted in ail increase of d-spacing. When coil homopolymers were added into triblock copolymer with a rod continuous hexagonally packed-cylinder structure, lamellar structures were obtained, and the lamellar d-spacing were smaller than that of the original Structure. The addition of rod-like homopolymer into the block copolymers with a lamellar structure also resulted in the increase of the d-spacing. As a result of the interdigitation, the rod blocks must rearrange to a larger angle with respect to the interface.