Nano-sized poly(ethylene glycol dimethacrylate-co-acylic acid) (poly(EGDMA-co-AA)) were effectively self-assembled on poly(divinylbenzene-co-styryl methylpyridinium chloride) (poly(DVB-co-StMPyCl)) surfaces to form the raspberry-like composite by a charge Compensation mechanism through the affinity complex between carboxylic group and pyridinium group. The effects of pH and salt electrolyte on the morphology of the self-assembled polymer composites were investigated. The resulting heterocoagulates were highly stable in water and acidic solution. These heterocoagulates were reversible through the self-assembly in acidic or neutral media and the discussion in the basic media due to the charge compensation through the strong affinity complex between hydroxide anion andpyridinium group cation. The resulting heterocoagulates were characterised with scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM) and fourier transform infrared spectrosropy (FTIR). As a result, a new method for tuning the structure of a charge compensation directed polymer composite was developed. (c) 2005 Published by Elsevier Inc.