Objective To study the time-course relationship of eotaxin mRNA and TNF-? mRNA expression in the lung tissue of sensitized mice after antigen challenge and the effects of Cryptoporus polysaccharide (CP) on these expression. Methods Eotaxin mRNA and TNF-? mRNA expression was determined by semi-quantitative RT-PCR. The function implications of eotaxin mRNA and TNF-? mRNA expression were examed by detecting the number of total leucocyte and eosinophils in bronchoalveolar lavage fluid (BALF). Results Peak level of TNF-? mRNA expression appeared at 8 h and eotaxin mRNA expression at 24 h in the lung tissue of sensitized mice after antigen challenge. Compared with the control group, total numbers of leukocyte and eosinophil in BALF increased in sensitized mice. CP 3, 10, and 30 mg/kg inhibited eotaxin mRNA and TNF-? mRNA expression, and inflammatory cells accumulation in airway of the sensitized mice in a dose-dependent manner. Conclusion The mechanism of inhibitory effects of CP on eotaxin mRNA and TNF-? mRNA expression may be related to the anti-allergic inflammation.