The quartz glasses were prepared by sintering of fumed silica powders and the effect of OH concentration on their surface on sintering was studied. Through the firing process, the fumed silica was crystallized from 1180 to $1260^{circ}C$ region. The amount of hydroxyl group decreased with increase in calcination temperature and consequently the crystallization was prevented. A transparent quartz glass was obtained from fumed silica, previously calcined at $1000^{circ}C$, by the sintering at $1250^{circ}C$ for 1 h.