I-doped Bi2Te3_xIx (x=0,0.05,0.1,0.2) flower-like nanoparticles were synthesized by a hydrothermal method through a careful adjustment of the amount of ethylenediamine tetraacetic acid surfactant.The nanopowders of flower-like nanoparticles were hot-pressed into bulk pellets and the thermoelectric properties of the pellets were investigated.The results showed that I-doping decreased the electrical resistivity effectively,and the thermal conductivitives of the Bi2Te3-xIx bulk samples was lower because of the closer atomic mass of I compared to Te.As a result,a ZT value of 1.1 was attained at 448 K for the Bi2Te2.9I0.1 sample.