The　independent　control　of　two　magnetic　electrodes　and　spin-coherent　transport　in　magnetic　tunnel　junctions　are　strictly　required　for　tunneling　magnetoresistance,　while　junctions　with　only　one　ferromagnetic　electrode　exhibit　tunneling　anisotropic　magnetoresistance　dependent　on　the　anisotropic　density　of　states　with　no　room　temperature　performance　so　far.　Here,　we　report　an　alternative　approach　to　obtaining　tunneling　anisotropic　magnetoresistance　in　alpha＇-FeRh-based　junctions　driven　by　the　magnetic　phase　transition　of　alpha＇-FeRh　and　resultantly　large　variation　of　the　density　of　states　in　the　vicinity　of　MgO　tunneling　barrier,　referred　to　as　phase　transition　tunneling　anisotropic　magnetoresistance.　The　junctions　with　only　one　alpha＇-FeRh　magnetic　electrode　show　a　magnetoresistance　ratio　up　to　20%　at　room　temperature.　Both　the　polarity　and　magnitude　of　the　phase　transition　tunneling　anisotropic　magnetoresistance　can　be　modulated　by　interfacial　engineering　at　the　alpha＇-FeRh/MgO　interface.　Besides　the　fundamental　significance,　our　finding　might　add　a　different　dimension　to　magnetic　random　access　memory　and　antiferromagnet　spintronics.