We synthesized a new hybrid nanocomposite consisting of CdSe quantum dot (QD) and regioregular poly (3-hexylthiophene)-b-poly (N,N-dimethylamino-2-ethylmethacrylate) rod-coil block copolymer to investigate the effects of nanoscale morphology to the photovoltaic properties in inorganic-organic hybrid solar cell. Well-defined conducting rod-coil block copolymers, P3HT-b-PDMAEMA, were synthesized by combination of Grignard metathesis polymerization (GRIM) and atom transfer radical polymerization (ATRP) methods. These rod-coil block copolymers were then mixed with oleic acid capped CdSe QDs through ligand exchange and characterized their nanoscale morphology and optoelectronic properties. These results can be explained by the effects of the bicontinuous electron-donor/electron-acceptor networks in active layer based on rod-coil P3HT-b-PDMAEMA block copolymers blended with CdSe QDs.