The new mineral fluorbritholite-(Ce) occurs in nepheline syenite，marble xenoliths，sodalite syenite xenoliths and pegmatite dikes at Mont St. Hilaire，Quebec，Canada. It is associated mainly with analcime，microcline，aegirine，zircon，biotite，pyrophanite，astrophyllite，ancylite，natrolite，monazite etc.. The mineral is hexagonal P63/m，with a=9.517(5)A,c=6.983(4)A，c/a= 0.7337 and V=547.7(8)A3;Z=2.The strongest X-ray powder diffraction lines and their relative intensities (visual)are:2.845(100)，2.747(10)，1.966(10)，1.865(10) and 1.825(10). Fluorbritholite-(Ce) crystal is shown prismatic. Color is pale yellow，tan and reddish brown. Streak colorless to pale brown;luster adamantine;opaque to translucent; hardness 5;brittle;cleavage {0001} distinct;fracture even to conchoidal;density 4. 66 (1)g/cm3 (meas.)or 4. 66 g/cm3 (calc.);non-fluorescent. Optically uniaxial(-)，ω=1. 792(5)，ε=1.786(5)in Na light;nonpleochroic. Electron microprobe analyses correspond to (Ca1.77Ce1.35 Lao.96 Ndo.21 Nao.21 Mno0.15 Sro.09 Pro.o8 Tho.o5 Yo.o2 Smo.o1)4.90 (Si2.17 Po.79)2.96 O11.95 F1.05.The ideal structural formula is (REE，Ca)5(Si，P)3 O12F. Ǻ