Abstract: Tc mN DCHDTC(DCHDTC: dicyclohexyl dithiocarbamate) is prepared through a two step ligand exchange reaction by using SnCl 2·2H 2O as reduction agent and SDH(succinic dihydrazide) as a donor of nitride nitrogen atom(N 3- ). The radiochemical purity of the product is over 95% by TLC. 99 Tc mN DCHDTC is stable over 6 h at room temperature. The lg P is 1.19.The electrophoresis results show the complex is neutral. The biodistribution results in mice indicate the complex has high blood uptake. The uptake ratios of blood/heart, blood/lung and blood/liver are 5.27,1.31 and 1.07 at 30 min post injection respectively. The results for the complex suggest that it will be potentially useful as a blood pool imaging agent.