Chemical and physical reactions during the low temperature aqueous chemical synthesis of nanostructured Bi2Te3 powders were investigated in-situ by pH measurement,color observation of the solution and X-ray diffraction analysis of the powders.It was found that Bi2Te3 could be synthesized only in a strong alkaline solution.Bi2Te3 nanocapsules were synthesized by the aqueous chemical route at 65℃ with the addition of disodium ethylenediaminetetraacetate salt.High-resolution transmission electron microscopy observation indicates that the nanocapsules are hollow-structured with a wall thickness of about 6 nm.