The up-conversion properties of Er3+ in the oxyfluoride glass-ceramics codoped with Er3+ and Yb3+ were studied using the 960 nm semiconductor laser as a pumped source.The green up-conversion fluorescence is a double-photon process,but the dependence of the green up-conversion fluorescent intensity on the pumped laser power are not quadratic.The saturation of the fluorescent intensity on the pumped laser power with increasing the pumped power is observed.These experimental phenomena could be well explained by the dynamic rate equations of the Er3+-Yb3+ system.It was concluded that the up-conversion properties in the oxyfluoride glass-ceramic were mainly influenced by the strong back transfer process between Yb3+ ions and Er3+ ions.