This　paper　presents　the　concept　of　evolution　ability　of　population　and　discusses　the　ability　of　finding　the　optimal　solution　for　the　population　after　one-generation　selection,　crossover　and　mutation.　Based　on　the　analysis　of　effect　of　selection,　crossover　and　mutation　on　evolution　ability　of　population,　this　paper　presents　some　important　conclusions.　These　conclusions　above　do　not　only　help　improve　the　GA,　but　also　provide　the　basis　for　later　research　work.　©2010　IEEE.