The aim of this study is to investigate the production conditions of silver nanoparticles in the presence of AgNO3 with the cytoplasmic fluid of white rot fungi Coriolus versicolor. In the study, parameters such as pH, AgNO3 concentration and cytoplasmic fluid ratio were optimized. The cytoplasmic fluid was obtained from fungus keeping in ultrapure water after grown in SBM. Nanoparticle formation was monitored by UV spectrophotometry at 420 nm wavelength and the silver nanoparticles were imaged by SEM. In the optimization study, it was found that at pH 5, the concentration of 1.5 mM AgNO3 and 50% of the medium containing the Coriolus versicolor cytoplasmic fluid were found to provide optimal conditions for the synthesis of the silver nanoparticle.