Comicellization of poly(4-vinylpyridine) and poly(ethylene glycol)-block-poly(acrylic acid) in ethanol is studied by static light scattering (SLS), dynamic light scattering (DLS),. and scanning electron microscopy (SEM). It is found comicellization takes place due to strong hydrogen bonding between poly(4-vinylpyridine) and the poly(acrylic acid) block when mixing poly(4-vinylpyridine) and poly(ethylene glycol)-block-poly(acrylic acid) in ethanol. The resultant micellar complexes are core-corona spheres with the hydrogen-bonded PAA/P4VP as core and the PEG as corona. Compared with typical amphiphilic block copolymer core-shell micelles, the present micellar complexes are much more swollen. Furthermore, it is also found the hydrodynamic diameter D-h, the gyration radius R-g(0), and the mass weight M-w of the micellar complexes can be easily tuned by changing the weight ratio of poly(4-vinylpyridine) to poly(ethylene glycol)-block-poly(acrylic acid).