Objective　To study the effects of irradiation and W11-a12，a kind of repair-promoting drug，on anion-selective channel in membranes of mouse peritoneal macrophage. Methods　The activity of anion-selective channel was recorded from cell-attached patches with patch clamp techniques． Results　The effects of irradiation on anion-selective channel in membranes of peritoneal macrophage included：①decreasing the mean number of activated channels by the presence of zymosan; ②prolonging the mean time from stimulus to the opening of channels; ③depressing the opening of channels by decreasing open-state probability，shortening open-time and prolonging close-time． The effects of irradiation could partly be depressed by W11-a12. Conclusion　Irradiation will depress the anion-selective channel of peritoneal macrophage, which may be an important way to depress the function of macrophage．