Abstract: Methods of extraction, separation, identification and about the antibacterial activity of acidic components from Ganoderma lucidum are investigated. The results showed that the yield of acidic components was 0 8%～1 1% of dry Ganoderma lucidum , when isolated by alkalinization from alcohol extract. Using n C 6H 14 /CH 2Cl 2/CHCl 3/MeOH(the volume ratio is 4 0∶3 0∶2 5∶0 5) as the mobile phase on silica gel film, the acidic components were identified as six major spots (S 1～S 6), with their R f values ranging from 0 54 to 0 12. The antimicrobial circle test showed that the acidic components at a concentration of 25 mg/mL had obvious action in bacteriostasis upon S.Aureus (G +) and E.coli (G -). Elution with CHCl 3/MeOH( V∶V =98∶2)(S 1) had bacteriostasis on E.coli , while elution with CHCl 3/MeOH( V∶V =50∶50)(S 5,S 6) exhibited bacteriostasis on S.Aureus . The above methods for extraction, separation and identification of acidic components from G.lucidum are simple and efficient. Furthermore, the obtained acidic components are controllable and bacteriostatic, and these may have potential medicinal application in antibacterial reagents.