In one hand, increasing pollution and global warming as one of the most important environmental concerns, increasing the price of asphalt, and on the other hand, the introduction of the transportation industry as one of the most common contaminant of environment raise the popularity of the use of warm mix asphalt (WMA) mixtures containing high percent of recycle asphalt pavement (RAP) in the construction of the asphalt pavement. This paper describes a laboratory effort that studied glass fiber modified warm mix asphalt mixtures with RAP contents of 0, 20, 40 and 50% to enhance resistance of mixture to rutting and moisture susceptibility. Parameters obtained from KNTU Wheel track test including the post compaction, stripping inflection point, dynamic stability and final cycles for 20mm and 12.5mm rutting depth were employed to evaluate rutting resistance and moisture sensitivity of the aged as well as the unaged samples. The results showed the improving impact of glass fiber and RAP percent on the performance of the WMA mixture.