Three organogermanium compounds synthesized by the authors including carboxyethyl germanium sesquioxide (Ge-132), carbamoylethyl germanium sesquioxide (CGS) and α,β-dicarboxyethyl germanium sesquioxde (DGS) could significantly stimulate mouse peritoneal macrophages (Mφs) which mediate MTC effect against mouse ascites hepatoma cells with high lymph duct metastatic capacity (HCa-F₂₅/16A₃-F) and human monocytoid leukemic cells by oral administration at one dose of 100 mg/kg.The CGS and DGS were more effective than Ge-132 in enhancing MTC effect at the above dose,and CGS had the strongest effect. The Mφs activated in vivo by CGS, DGS and Ge-132 at one dose of 100 mg/kg showed increased incorporation of ［³H］ choline into phosphatidylcholine (PC), and the most significant increase was observed when Mφs were activated by DGS. Mφs activated in vivo by Ge-132 also showed increased incorporation of ［³²P］Pi and ［³H］choline into PC, and decreased incorporation of ［³²P］Pi and ［³H］inositol into PI when compared with resident peritoneal Mφs. No significant difference was observed on the incorporation of ［³²P］Pi and ［³H］inositol into polyphosphoinositide (PIP and PIP₂） between the Ge-132 activated Mφs and the resident peritoneal Mφs. The enhanced PC turnover of Mφs might be necessary for the expression of MTC in activated Mφs.