To　predict　the　mechanical　response　of　IN718　alloy　under　various　complex　conditions　accurately　and　reliably,　the　theoretical　modeling　of　serrated　plasticity　of　microsized　single-crystal　IN718　alloy　under　displacement　control　was　carried　out.　Starting　from　the　micro-compression　test,　a　simple　deformable　body-spring　model　was　proposed　to　further　elucidate　the　serrated　plasticity　under　the　displacement　control.　Subsequently,　the　independent　modeling　elements　such　as　strain　hardening,　flow　rule,　loading-unloading　criterion,　and　strain　burst　criterion　were　taken　into　consideration.　Then,　a　continuum　constitutive　model　for　the　serrated　plasticity　was　established.　This　model　was　used　to　study　the　compression　response　of　IN718　micropillars　with　single　slip　and　double　slip　orientation,　respectively.　The　simulations　produced　clearly　a　series　of　visible　strain　bursts,　loading　and　unloading　process　in　micropillar　plasticity,　and　the　exhibited　serrated　flows　are　comparable　with　the　corresponding　experimental　observations.　The　proposed　continuum　model　for　the　serrated　plasticity　can　provide　a　strong　theoretical　support　for　the　development　of　the　classical　crystal　plasticity　theory　in　the　sub-micron　scale.　©　2019,　Editorial　Board　of　Journal　of　Harbin　Institute　of　Technology.　All　right　reserved.