Cyclic core dendritic polymer is a new type of synthetic polymer. We describe the first serial dendrimers with a core of 1,4, 7, 10-tetraazacyclododec ane. The abili ty of generation 4 of dendrimers to function as an effective gene delivery vectors was also investigated. Results from fluorescent in situ hybridization (FISH) show that the dendrimer has good affinity to both DNA and human small intestine cancer metastatic (HICMA) cells. the LacZ gene was highly expressed in the cells.