A facile synthesis route has been developed to prepare barium titanate nanoparitcles via a low temperature (120 degrees C) hydrothermal decomposition of single-source metal-organic precursor. A mixture of tetramethylammonium hydroxide (TMAH) and distilled water was used as reaction media, and Barium titanium ethylw-hexanoisoproxide [BaTi(O2CC7H15)(OC3H7)(5)] was used as precursor. The architecture of products can be selectively controlled from nanorods to nanospheres by adjusting the precursor's concentration in the reaction system. Powder Xray diffraction (XRD) analysis indicated that the products were in cubic phase. Transmission electronic microscopy (TEM) observation showed that the nanospheres were 30 similar to 50 nm in diameter, and the nanorods were 5 similar to 10 nm in diameter and 100 similar to 600 nm in length, respectively. Phase transformation behavior of the as-prepared products was also investigated.