Poly(vinyl cinnamates) (PVCi) with different degrees of substitution (DS) are synthesized by grafting p-chloro-substituted cinnamic acid onto poly(vinyl alcohol). The chemical structures of PVCi were confirmed by 1H NMR. Amphiphilic PVCi copolymers were self-assembled into particles in a selective solvent. The morphology and diameter of particles have been studied by scanning electron microscopic and dynamic light scattering. The morphology and hydrodynamic diameter have strong relationship with DS and water content introduced during self-assembly process. The prepared PVCi could photo-cross-link at = 360 nm due to the photodimerization between pendant cinnamate groups. However, the self-assembled PVCi particles did not present photo-crosslinking behavior. The formed regular particles could disperse in aqueous solution, which increases their applications in biomedical fields. POLYM. ENG. SCI., 2013. (c) 2012 Society of Plastics Engineers