Abstract: We carried magnetic treatment for 9 times on ordinary water with field strength of 0.1, 0.25, 0.4T，while treating the series connection（SC）3 times, in flow velocity for 1.0 m·s^-1 and the distance of 30 cm,respectively to culture. Furthermore,the influence of different magnetic field strength on biological efficiency, cordycepin, cordycepic acid(D-mannitol), polysaccharide by the fruiting body of Cordyceps militaris were investigated. Under the same condition,the 0.4T treatment was favorable for and cordycepic acid production and fruiting body growth,which increased 7.29 % and 15.37% compared with the contrast ,respectively. The 0.25T treatment was favorable for cordycepin production of C.militaris,which increased 11.31% compared with the contrast. The 0.1T treatment was favorable for polysaccharide production in the fruiting body of C.militaris,which increased 14.80% compared with the contrast. ANOVA showed that different magnetized water had significant effect on fruiting body growth and active substance production. Besides, the influence rules of magnetized water on different substance existed differences.

Key words: biomagnetic effect, Cordyceps militaris, biological efficiency, bioactive metabolite