Six diorganotin phenoxy acetic acid containing silicon were synthesized by the reaction of diorganotin oxides with phenoxy acetic acids;and their structures were characterized by IR,1HNMR,13CNMR,elemental analysis.The preliminary bioassay tests showed that(Me3SiCH2)2Sn(OCOCH2C6H4CH3-p)2 exhibited a good antitumour activity in vitro against lung tumour cells A549 and colorectal tumour cell SW480.