To　reduce　the　complexity　of　High　Efficiency　Video　Coding　(HEVC),　this　paper　focuses　on　innovative　works　for　fast　coding　tree　unit　(CTU)　depth　decision　in　HEVC　intra　coding　based　on　a　proposed　CTU　depth　range　possibility　mechanism.　First,　the　depth　correlation　factor　(DCF)　is　computed　by　analyzing　the　temporal-spatial　correlation　of　the　co-located　CTU　and　its　spatial　adjacent　CTUs　in　previous　frame.　Second,　the　most　possible　depth　range　(MPDR)　of　current　CTU　is　predicted　according　to　DCF　and　the　known　coding　depth　information　of　neighboring　CTUs　in　current　frame.　Experimental　results　show　that　the　proposed　method　can　achieve　34.06%　coding　time　saving　on　average　with　1.36%　BDBR　increase　and　0.12　dB　BDPSNR　decrease　compared　with　HM15.0.　The　proposed　method　is　expected　to　be　applied　in　the　real-time　environments.