Fine　structure　and　hyperfine　structure　Mn2+　in　LiNbO3　are　analyzed　with　electron　spin　resonance　(ESR)　at　room　temperature.　It　is　concluded　that　the　zero-field　splitting　of　enery　levels　of　electron　spin　angular　moment　between　\　+/-(1)/(2)＞　and　\　+/-　(3)/(2)　＞　is　Deltaepsilon(1)　=　-587　x　10(-4)cm(-1),　and　that　between　\　+/-(3)/(2)　＞　and　\　+/-　(5)/(2)　＞　is　Deltaepsilon(2)　=　-2633　x　10(-4)cm(-1).　The　anisotropic　Lande　factors　are　g(//)　=　2.1810,　and　g(perpendicular　to)=　2.0937.　The　fine　structure　constant　is　D　=　-536　x　10(-4)cm(-1),　and　hyperfine　structure　constants　are　A(//)　=　88.36cm(-1)　and　A(perpendicular　to)　=　81.20　x　10(-4)cm(-1).　The　interaction　action　of　the　fine　structure　is　larger　than　that　of　the　hyperfine　structure.　In　addition,　it　is　worth　paying　special　attention　to　the　fact　that　two　forbidden　transitions　\　-(3)/(2)　＞　＜----＞　\　(1)/(2)　＞　and　\　-(1)/(2)　＞　＜----＞　\　(5)/(2)　＞　are　found.