Investigation　into　the　temperature　dependence　of　the　mechanical　behavior　of　ultra-coarse　grained　cemented　carbide　materials　is　highly　demanded　due　to　its　service　conditions　of　concurrent　applied　stress　and　high　temperature.　In　the　present　study,　based　on　the　designed　experiments　and　microstructural　characterization　combined　with　crystallographic　analysis,　the　evolution　of　slip　systems,　motion　and　interaction　of　dislocations　with　temperature　are　quantified　for　the　WC　hard　phase.　Mechanisms　are　proposed　for　the　formation　of　the　sessile　dislocations　in　the　main　slip　systems　at　the　room　temperature　and　the　glissile　dislocations　in　the　new　slip　systems　activated　at　high　temperatures.　Furthermore,　the　correlation　of　the　plastic　strain　and　fracture　toughness　with　the　temperature-dependent　slip　activation,　dislocation　reaction　and　transformation　is　explained　quantitatively.　Enlightened　by　the　present　findings,　potential　approach　to　enhance　the　high-temperature　strength　of　ultra-coarse　cemented　carbides　based　on　WC　strengthening　was　suggested.