SELinux　is　a　strong　and　flexible　system　with　a　well-defined　MAC　architecture.　It　provides　a　mechanism　to　enforce　the　access　control　based　on　confidentiality　and　integrity　requirements　which　offers　an　effective　protection　of　information　security.　This　paper　describes　in　what　way　SELinux　uses　various　models　and　policies　to　secure　the　information　safety　which　different　from　others,　especially　from　a　special　perspective　to　represents　how　multilevel　security　policy　and　type　enforcement　provide　confidentiality　and　integrity　protection.