Pure-phase cerium-doped yttrium silicate and yttrium disilicate phosphors were successfully synthesized by the sol-gel method with added ammonia when the precursor was calcined at 1100• C and 1300• C for 1 h. The blue light was emitted when excited by the UV radiation of 325 nm wavelength. The luminescence of Y2SiO5:Ce1% phosphors was less than that of Y2Si2O7:Ce1% in the same synthetic condition. Besides, their photoluminescence was strongly increased when Li, Na or K sensitizers were added. The X1-Y2SiO5 and X2-Y2SiO5 phosphors were irregular shapes and composed of agglomerates with the particle size of approximately 70 nm to 100 nm.