A series of Yb3+/ Er3+ codoped transparent oxyfluoride glass ceramics with various amounts of Yb3+ have been successfully fabricated and characterized. Under 980 nm laser prompting, the samples produce intense red, green and blue up-conversion emissions, and the emission intensities increase with Yb3+ concentration and heat treatment temperature. Before losing good transparency in the visible region, optimum emission intensities are obtained for the sample with 25 mol % of Yb3+ at a heat treatment temperature of 680℃. A possible up-conversion mechanism is proposed from the dependence of emission intensities on pumping power. The fluorescence intensity ratio between the two thermally coupled levels 2H11/2 versus 4S3/2 was measured with the laser output power of 57 mW to avoid the possible laser induced heating effect.