For　study　on　the　nonlinear　creep　model　of　T2b2　siltite　in　the　Three　Gorges　reservoir　area,　a　nonlinear　viscoelasticity　model　that　can　well　describe　the　creep　property　of　siltite　is　established　and　the　parameters　are　also　obtained.　Based　on　nonlinear　rheological　theory　and　stress-strain　relation　of　T2b2　siltite,　a　modified　Kelvin　model　and　its　creep　equation　are　presented　firstly.　Through　installing　the　swath　model　which　can　be　expressed　as　a　step　function　with　N　model　in　parallel,　a　revised　N　model　is　established.　What＇s　more,　through　connecting　revised　N　model　with　revised　K　model　and　H　model　in　the　form　of　series,　an　mBurgers　model,　which　can　well　describe　the　nonlinear　creep　property　of　rock　is　established.　According　to　nonlinear　least　squares　theory　and　uniaxial　creep　test　results　of　T2b2　siltite,　the　parameters　of　mBurgers　model　are　obtained　by　inversion　calculation.　By　substituting　the　parameters　obtained　on　behalf　of　the　inversion　into　the　model　and　calculating　the　theoretical　results,　theoretical　curve　and　test　curve　are　well　anastomotic,　which　indicates　that　mBurgers　model　can　well　describe　the　creep　of　T2b2　siltite.