Glasses being prepared, measurements and investigations of glass transition temperature and IR edge optical absorption have been performed for the compositions of 56ZrF4-14BaF2-6LaF3-4AlF3-(20-x)NaF-xLiF. Values for transition temperature of these glasses decrease in proportion to increasing LiF mol%(x) in the range of 0<x<9, whereas it shows constant value (533K) regardless of x at higher LiF concentration (9<x<20). IR edge optical absorption increases are directly proportional to increasing x, and values of IR edge optical absorption coefficient exhibit exponential like decreases with increasing wave numbers for all the glasses.