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.