The　electron　backscattered　diffraction　technique　was　used　to　identify　the　orientation　textures　of　both　grains　and　boundary　planes　in　a　hot　deformed　SmCo5　permanent　magnet.　The　results　show　that　the　orientations　of　SmCo5　grains　are　strongly　textured　and　the　{0001}　orientations　are　remarkably　preferred.　Moreover,　grain　boundary　planes　are　also　textured.　Three　symmetry　equivalents　of　Sigma　13a　boundaries,　namely　the　27.796　degrees/[0001]　boundary,　the　32.204　degrees/[0001]　boundary　and　the　92.204　degrees/[0001]　boundary,　are　favored,　and　the　occurring　frequency　of　Sigma　13a　boundaries　is　5　times　higher　than　that　of　the　random　boundaries.　Potential　effects　of　the　orientation　textures　of　grains　and　boundary　planes　on　the　magnets　are　also　proposed.