The　microstructure,　thermal　and　mechanical　stability　of　Ni-based　single　crystalline　superalloys　depend　strongly　on　the　alloying　elements　and　their　concentrations.　Alloying　has　been　the　main　design　strategy　for　stabilizing　the　compositions,　microstructures　and　thermal-mechanical　properties.　This　article　presents　a　review　on　the　effects　of　some　common　alloying　elements　on　the　microstructural　and　mechanical　property　stability　control　of　Ni-based　superalloys.　The　various　alloying　elements　are　divided　into　four　categories　according　to　their　main　effects　on　these　properties,　comprising　base　elements,　mechanical　strengthening　elements,　long　term　stability　elements　and　the　oxidation　resistance　elements.　The　mechanical　strengthening　elements　can　further　be　divided　into　precipitation,　solid　solution　and　grain　boundary　segregation　elements.　The　precipitation　elements　strengthen　the　alloys　by　forming　the　L1(2)　structured　gamma＇　phase.　The　solid　solution　elements　strengthen　primarily　the　gamma　phase,　by　increasing　the　solidus　temperatures　and　decreasing　the　stacking　fault　energy,　which　in　turn　influences　the　thermal　stability　of　the　phases　and　the　resistance　of　dislocation　movement.　The　grain　boundary　elements　strengthen　the　alloys　by　the　formation　of　carbides　and　borides　along　the　grain　boundaries　during　solidification,　which　help　to　prevent　the　formation　of　casting　pores　and　hot　tearing　and　to　strengthen　low　angle　boundaries.　The　long-term　stability　elements　inhibit　the　precipitation　of　topologically　closed-packed　phases　causing　deterioration　of　the　mechanical　properties.　The　oxidation　resistance　element,　mainly　Al,　promotes　the　formation　of　protective　Al2O3　surface　layer.　(c)　2018　Elsevier　B.V.　All　rights　reserved.