The aim of the present study was to isolate and identify parasites and saprophytes from fungal affected eggs of Rainboe trout.The samples(n= 900) were obtained from six fish farm and transferred to mycology laboratory in stril tubes. The samples were inoculated in cculture media, (SDA, CMA, GPagar and hemp seeds cultures) at room temperature (18-24°C). Twelve species of fungi isolated from the fungal eggs. Three isolated fungi were belonged to the saprolegniaceas' family including : Saprolegnia parasitica, Saprolegnia sp., Achlya sp. Other nine fungi were: Penicillium, Aspergillus, Paeciliomyces, Acremonium, Fusarium oxysporum, F.solani, Alternaria, Mucor and Helminthosporium. In this study three species of pathogenic aquatic fungi were Saprolegnia parasitica, Saprolegnia sp., Achlya sp. It seems that saprolegnia parasitica was the most important fungal egg infestation in Mazandaran salmonid hatcheries. Meanwhile, saprophytic fungi can help for spreading of fungal egg infection