Objectives This experimental study was carried out to evaluate the effects of Phellinus Linteus on immune activation. Methods In order to investigate the effect of Phellinus Linteus, the following was performed: The fraction of $CD4^+$, $CD8^+$, $CD19^+$ in splenic cell, gene expression of IL-12 (p35), IL-12 (p40) , $IFN-{gamma}$, and splenic cell proliferation by PL-E. Results PL-E helped $CD4^+$, $CD8^+$, $CD19^+$ expression more effectively compared with control group. PL-E helped IL-12 (p35), IL-12 (p40), $IFN-{gamma}$ gene expression in splenic cells more effectively compared with control group. PL-E proliferated splenic cells more effectively compared with control group. Conclusions: It is suggested that PL-E is able to activate immune response system.