In this paper, the Zn-based analogue of Cu3(btc)2 (HKUST-1), Zn3(btc)2 nanorods (Zn-HKUST-1; btc=1,3,5-benzenetricarboxylate) have been synthesized through direct precipitation in solution phase under ultrasound condition without the assistance of any surfactant, catalyst, or template. Zn-HKUST-1 nanorods werecharacterized by Fourier transform infrared studies, elemental analysis, powder X-ray diffraction and field emission scanning electron microscopy. Concentration of initial reagent effects on size and morphology of the Zn-HKUST-1 has been studied and shows that low concentrations of initial reagents decreased widths, thicknesses, and lengths of nanorods. Subsequently, ligand-free ZnO nanorods and nanoparticles are selectively prepared via a thermal decomposition method using the corresponding nanorods and single crystals as a precursor, respectively. This solid-state transformation route is promising for the preparation of crystalline nanomaterials with desired morphologies because of its simplicity and the low cost of the starting reagents.