CeSi 3 N 5 has been prepared via the polymer route, a one-pot and liquid-phase synthesis, based on a reaction between SiCl 4 and liquid NH 3 in which Ce[N(Si(CH 3 ) 3 ) 2 ] 3 was suspended. The sample was characterized by powder X-ray diffraction analysis, diffuse reflection and photoluminescence spectroscopies. CeSi 3 N 5 exhibits a strong absorption peaking at 365 nm. Furthermore, it has a broad emission band at 468 nm due to 4f 0 5d 1 → 4f 1 transition of Ce 3+ . Obviously, CeSi 3 N 5 appears to be a good candidate for use as a blue phosphor, which can be pumped by near-UV-LEDs.