To obtain high yield of selenium enriched Hericium erinaceus mycelium,a selenium tolerant variety from H2,H99 and NK was selected by the plate method via the Na₂SeO₃ concentration gradient experiment.Then the medium components including carbon source,nitrogen source,inorganic salt and vitamin were optimized with orthogonal test based on single factor test,followed by the proportion of nutrient elements determined via uniform design.And the Na₂SeO₃ concentration in deep fermentation medium was determined based on dry weight of mycelium,content of total selenium and organic selenium.The results showed that:among the three H. erinaceus strains,H2 was the most selenium tolerant,and the mycelium cultured in plate medium containing Na₂SeO₃ 6 μg/mL was suitable for the subsequent research.The optimized liquid medium composition was as follows:5.8% soluble starch,5.8% soybean powder,0.04% CaCl₂,0.024%,VB₁+VB₂+VB₆,and the theoretical value of mycelium dry weight could reach 2.37 g/100 mL.The mycelial growth in liquid medium containing 12 μg/mL Na₂SeO₃ was not inhibited and content of organic selenium was the highest of 136.8 mg/kg.This study laid a foundation for the development and utilization of selenium enriched H. erinaceus.