Under ordinary pressure，3-D flower-like ZnO nanomaterials were successfully synthesized by two steps of sol-gel and chemical solution growth methods with three different substrates.The samples were characterized by means of X-ray diffraction（XRD）,scanning electron microscopy（SEM），transmission electron microscopy（TEM），selected-area electron diffraction（SAED），ultraviolet absorption spectroscopy and photoluminescence spectrum（PL）.The results indicated that the component units of flower-like ZnO were ZnO nanorods grown along the c-axis.The diameter and length of nanorods were approximately 100 nm and 2 μm,respectively.Different substrates had little effect on the morphology of flower-like ZnO and the solution pH value had great influence on the formation of flower-like ZnO.The ultraviolet absorption spectrum and photoluminescence spectrum of 3-D flower-like ZnO nanomaterials indicated that the nanomaterials produced a strong broadband absorption in ultraviolet area，a strong blue emission at 421 nm and two weak green emissions at 520 nm and 560 nm.Therefore，this flower-like ZnO could be used to make the blue light emitting devices.