Rock　mass　characteristics　(RMC)　model　is　the　one　of　serval　prediction　models　for　TBM　penetration　rate　that　considers　the　interaction　between　the　rock　mass　and　cutters.　The　first　version　was　developed　in　2009.　However,　it　was　a　relative　site　specific　model　and　the　machine　parameters　were　ignored.　To　update　the　RMC　model,　a　comprehensive　data　base　which　included　the　results　of　the　laboratory　cutting　tests　and　the　in　site　penetration　tests　was　compiled.　Firstly,　the　correction　factors　of　the　cutter　spacing　and　cutter　shape　were　set　up　based　on　the　laboratory　tests,　which　were　then　used　to　normalize　the　data　with　the　given　machine　parameters.　Finally,　two　critical　parameters　in　RMC　model,　i.e.,　the　specific　rock　mass　boreability　index　(SRMBI)　and　the　exponent　c,　were　estimated　by　regression　analysis　using　the　rock　mass　parameters.　Now　SRMBI　in　the　updated　model　represents　the　boreability　of　a　rock　mass　excavated　by　the　given　machine　setup　at　penetration　rate　of　1　mm/rev.　A　higher　SRMBI　implies　the　rock　mass　is　more　difficult　to　be　bored.　The　exponent　c　decides　the　increment　in　cutter　normal　force　for　the　increasing　penetration　rate,　c　together　with　the　rock　mass　strength　reflect　the　different　TBM　cutting　modes.　Since　the　rock　specimens　in　the　laboratory　tests　was　intact　and　the　rock　masses　in　the　in　site　penetration　tests　contain　the　joints,　the　updated　model　reflects　the　reduction　in　the　required　thrust　force　caused　by　the　joints　in　nature.　The　updated　RMC　model　covered　a　wide　range　of　the　geological　context　and　machine　parameters.　It　could　be　used　to　predict　TBM　penetration　rate　and　optimize　the　operating　parameter　in　the　given　stroke.　The　equations　in　the　updated　model　need　further　modification　when　more　test　data　is　collected,　and　the　in　situ　stress　needs　to　be　taken　into　consideration.