 Chytosan nanoparticles were prepared from low and high molecular weight Chytosan and its derivative, trimethyl Chytosan, TMC, and found to have better inhibitory activity against Candida albicans and Fusarium Solani compared to the solution form. The inhibitory effect was influenced by particle size and Zeta potential of Chytosan nanoparticles, while Aspergillus Niger was resistant except for nanoparticles prepared from higher concentrations of high molecular weight Chytosan. Chytosan nanoparticles could be formulated and applied as a natural antifungal agent to enhance its activity. This article was authored by Lin Yaning, Norazia Mohamedzin, Tief Sawa, and others.