A novel route to synthesize crosslinked porous polyvinylamine (PVAm) microspheres from acrylonitrile (AN) was developed. In the first step, crosslinked porous polyacrylonitrile (PAN) spheres were prepared by copolymerization of AN and divinylbenzene (DVB). Then they were hydrolyzed to form polyacrylamide (PAM) spheres. And lastly, the porous PVAm spheres were successfully obtained via Hofmann degradation of PAM spheres. Scanning electron microscope (SEM) indicated that these PVAm microspheres have rough surfaces and porous interior structure. The pore size, the amino content, and the content of equilibrium water were also investigated. The pore size of these PVAm microspheres increased with the hydrolytic process. The contents of equilibrium water was changed from 49.6 to 96.5% depending on the different crosslinking degrees, and the amino contents were varied between 9.60 and 15.30 mmol/g depending on the different molar ratio of n(NaClO)/ n(NaOH). (c) 2008 Wiley Periodicals, Inc.