Beta-chitosan has a parallel structure, which differs from alpha-chitosan’s antiparallel structure while
producing different properties and difficulties. In this paper, we prepared the beta-chitosan through
acid and alkali methods and the resultant material was characterized by elemental analysis, FT-IR, HPLC,
XRD, NMR and AFS. To increase the solubility and biological activity of the beta-chitosan, we degraded
it through microwave-assisted process. After characterization, we determined that the chitosan had not
changed its configuration during the reaction with H2O2 under microwave irradiation. The inhibitory
activity of the degraded chitosan for Newcastle disease was revealed by a hemagglutination test and
RT-PCR. The yield of the beta-chitosan was approximately 30%, and its molecular weight can be degraded
to 1000 to 10,000 g/mol. Moreover, the degraded -chitosan has higher antiviral activity, reducing the
hemagglutination titre to zero, compared with alpha-chitosan. Therefore, beta-chitosan has good development
prospects during the development of veterinary drugs for Newcastle disease.