This　paper　examines　characteristics　of　active　learning　and　its　practice　currently　being　taken　by　the　operating　system　course　in　our　computer　science　college.　Several　kinds　of　practice　mode　are　discussed　while　taking　into　account　different　stages　including　lecture,　experiment,　and　assignments.　The　teacher＇s　responsibility　and　common　challenges　is　addressed.　By　virtue　of　active　learning,　both　the　teaching　capability　of　teachers　and　the　learning　ability　of　students　are　improved　greatly.　The　students＇　studying　interest　is　greatly　motivated　and　overall　teaching　effects　are　better　than　before.