The combination of self-consistent field theory and density functional theory was extended to investigate the self-assembly behaviors of amphiphilic diblock copolymer/nanoparticle mixture in dilute solution. The presented theoretical system includes solvophobic-solvophilic diblock copolymer and solvophobic nanoparticles, where the nanoparticles are attractive to solvophobic blocks and repulsive to solvophilic blocks. The dumbbell-like micelles were discovered at low loading of nanoparticles, while the sphere-like micelles were formed at relative high loading of nanoparticles. It was found that the nanoparticles favor the center of the cores in the dumbbell-like micelles but prefer to localize in an internal shell between the center of the cores and solvophobic/solvophilic interfaces in the sphere-like micelles. It also revealed that the morphology transformation from dumbbell-like micelles to sphere-like micelles is entropy-driven. (C) 2018 Published by Elsevier B.V.