Among　the　existing　video-related　applications,　a　large　proportion　have　requirements　for　the　scalability　of　the　video　coding　complexity,　such　as　live　video　chatting　and　video　coding　on　power-limited　mobile　devices.　Hence,　the　complexity　control　algorithms,　which　aim　to　make　an　effective　and　flexible　tradeoff　between　coding　complexity　and　rate-distortion　(RD)　performance,　have　a　great　practical　value.　In　this　paper,　a　novel　complexity　control　scheme　for　high　efficiency　video　coding　(HEVC)　is　proposed　by　dynamically　adjusting　the　depth　range　for　each　coding　tree　unit　(CTU).　To　control　the　complexity　accurately,　a　statistical　model　is　proposed　to　estimate　the　coding　complexity　of　each　CTU.　Then　the　complexity　budget　is　allocated　to　each　CTU　proportionally　to　its　estimated　complexity.　At　last,　the　depth　range　is　optimized　for　each　CTU　based　on　the　allocated　complexity　and　the　probability　that　contains　the　actual　maximum　depth.　Our　method　works　well　even　if　the　ratio　of　target　complexity　to　full　complexity　drops　to　40%,　The　experimental　results　show　that　our　proposed　method　outperforms　other　four　state-of-the-art　methods　in　terms　of　the　RD　performance,　and　has　superior　complexity　control　accuracy　and　complexity　control　stability　compared　with　other　one-pass　complexity　control　strategies.