AIM: To deplore the adjustion of whole peptidoglycan of bifidobacterium bifidum to functions of macrophages.METHODS:Levels of interleukin 6, interleukin 12 produced by peritoneal macrophages of nude mice was detected by ELISA method, and the content of nitric oxide (NO) was detected by using Griess reagent, after whole peptidoglycan were injected into nude mice peritoneally. RESULTS:The content of interleukin 6, interleukin 12 and NO secreted from peritoneal macrophages of nude mice in the whole peptidoglycan injection group was 732.54?190.30(pg/mL)、816.37?96.40(pg/mL) and 48.90?6.51(?mol/L) respectively.It was 303.78?171.75(pg/mL), 510.27?123.46(pg/mL) and 30.67?12.83(?mol/L) respectively in the control group. In view of the content of interleukin 6, interleukin 12 and NO, there existed significant difference when whole peptidoglycan injection group was compared with control group( P