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In order to obtain the inviscid dendrimers with more terminal amino-groups than those of ω,ω′-polyethylene glycol diamine, in the meanwhile to untilize the fine biocompatibility of polyethylene glycol,a series of polyamidoamine dendrimers with polyethylene glycol core were synthesized by Tomalia's divergent method which invovled a repeated two-step process:(1) exhaustive Micheal addition of ω,ω′-polyethylene glycol diamine as the initiating core,with methyl acrylate and (2) exhaustive amidation of the resulting esters with a large excess of ethylenediamine. The structures of all generations of the dendrimer was identified by FT-IR and elemental analysis, and the numbers of the terminal aminogroups of the integral generations of the dendrimer were determined by potentiometer titration.Although PEG-NH-2 and the integral generations had adsorption at ～3300 cm-1 in FT-IR, the half generations did not have. It indicated that all the steps of Micheal addition took place thoroughly.On the other hand, the conversion of the half generations into their corresponding integral generations made the adsorption of the ester's carbonyl at 1735～1740cm-1 disappear,it suggested that the conversion was complete.The results of elemental analysis also affirmed the above discussion.However the data of elemental analysis and potentiometer titration of PEG-5^0 and PEG-6^0 didn't entirely coincide with their theoretical values,that may be due to the residue of the ingredients such as ethylenediamine which were bundled up by larger generations with more branches and difficult to remove.Except that PEG-1^0 and PEG-2^0 are solids,the other integral generations are viscous. Influences of the integral generations on coagulation and hemolysis were examined,and the results showed that the properties of coagulation and hemolysis of the integral generations of the dendrimer were similar to those of polyehylene glycol.