olyphophates as liposome preparing materials were synthesized. These new amphiphilic polyphosphates were synthesized by polycondensation of β-bromoethyl dichlorophosphate and α-monostearin in benzene

and then by quaterisation with alkyldimethyl amine. Their chemical structures were comfiremed by IR

1HNMR spectra and elemental analyses. Average molecular weight of polymer prior to quaterisation was determined by VPO method. The nitrogen content from elemental analyses showed that the quaterized polymers containing different content of quaternary ammonium side chain (50-31%). These polyphosphates were used to prepare liposome by using Reverse phase evaporation method. All quaterized poly-phosphates could form large unilamellar liposomes. The diameter of liposome from polyphosphate IIa is 104nm. All the experimental data showed that these am-phiphilic polyphosphates are good materials for preparing liposomes. The encapsulation ratio of 5-Fluorouracil (5-Fu) was determined Encapsulation ratio of 5-Fu is in the range of 25% to 32% Release rate of 5-Fu from liposome was also studied.