Abstract: The silica glass doped with Er3+ and Al3+ iones were synthesized through sol-gel process.The effect of Al3+ on luminescence properties of Er3+ was studied.The results show that the concentration of Er3+ in co-doped silica glass can be improved one time than Erdoped glass,and the intensity is 20 times than that of Al non-doped glass.We concluded that the relation between Al3+ and Er3+ is just not energy transfer,but is that Al3+ not only change the configuration of sample,but also disperse the Er3+,as a result,the odds of cross-relaxation is depressed.And find that Er3+ iones have only an up-conversion emission at 654nm using 980nm excitation.