The present invention relates to a phosphor for UV and long-wavelength excitation and a preparation method thereof, more particularly to a phosphor for UV and long-wavelength excitation prepared from a phosphor precursor comprising strontium, barium, zinc, silica and rare-earth metal, wherein the proportion of barium and zinc is optimized to obtain a color coordinate in the range of x=0.50-0.64 and y=0.38-0.51, and a method for preparing the same by heat-treating the phosphor precursor under a mixed gas atmosphere of nitrogen and hydrogen with specific proportion. Since heat treatment is possible even at low temperature, a phosphor for UV and long-wavelength excitation having superior luminescence characteristics and thus offering superior efficiency when applied to diodes or liquid crystal displays can be obtained without having to use conventional flux materials to lower baking temperature and without using toxic substances.