This study aimed to demonstrate the activity of nanomaterials, the mechanisms of their biosynthesis, methods of measurement, and the factors that roles their biosynthesis by fungi. Moreover, focusing on their impact on host resistance against fungal pathogens. Nanometerials have been considered as one of scientific research priorities due to their new features (melting temperature, binding energy, electronic structure and catalytic activity, magnetic properties, dissolving temperature, and hardness). The performance and efficiency of nanomaterials compared to their normal state has been proven in many fields such as health care, agriculture, transportation, energy, information and communication technology. Many mechanical, chemical and physical methods were implemented to produce nanoparticles, which are considered as unsafe, expensive and environmentally dangerous. Therefore, researchers interested in biosynthesis of nanoparticles using fungi, bacteria or plants systems to make the process environmentally and economically safe. Furthermore, microorganisms such as yeasts, fungi and bacteria efficiency of converting inorganic ions into metallic nanomaterials was well studied. In agriculture, studies have confirmed impact of nanoparticles in improving plant productivity and pathogens resistance in different approaches like direct spraying on plants, soil, and stored fruits in a curative and preventive modes.