The　influence　of　uniaxial　tensile　strains　with　different　orientations　to　the　conduction　channel　on　the　electrical　and　physical　properties　of　AlGaN/GaN　high-electron-mobility　transistors　(HEMTs)　was　investigated.　The　output　current　decreases　with　the　increase　of　the　tensile　strain　as　the　orientation　of　strain　changes　from　0&#with　respect　to　the　conduction　channel.　The　results　of　the　measured　curves　show　that　for　the　same　strain　level　the　two-dimensional　electron　gas　(2DEG)　density　decreases　monotonically　to　different　extents　depending　on　the　strain　orientation.　A　conversion　of　the　strain　at　different　orientations　to　an　equivalent　strain　parallel　to　the　conduction　channel　shows　that　the　theoretical　resultant　changes　of　the　2DEG　density　are　consistent　with　the　experimental　results.　The　corresponding　electron　mobility　is　also　calculated,　which　shows　a　decreasing　trend　under　the　tensile　strain.　Furthermore,　using　the　transient　current　method,　it　is　established　that　the　detrapping　time　constant　increases　as　a　result　of　the　tensile　strain,　which　is　ascribed　to　the　movement　of　the　trap　level　away　from　the　conduction　band.