Static　performance　evaluation　is　one　of　the　most　important　issues　during　the　design　stage　of　tripod　parallel　kinematic　machines.　Taken　the　1T2R　tripods　as　examples,　this　article　proposes　two　improved　static　performance　indices,　namely,　local　dexterity　stiffness　index　and　global　dexterity　stiffness　index.　By　combining　the　local　dexterity　formulation　and　the　eigenstiffness　matrix,　the　two　indices　can　be　derived,　which　considers　both　the　kinematic　dexterity　and　the　static　rigidity　of　the　tripod　parallel　kinematic　machines.　Based　on　this　concept,　the　indices　of　local　dexterity　stiffness　index　and　global　dexterity　stiffness　index　are　defined　for　the　local　and　global　static　performance　of　the　parallel　kinematic　machines,　respectively.　With　the　index　of　local　dexterity　stiffness　index,　the　static　performance　distribution　of　an　Exechon　parallel　kinematic　machine　over　its　entire　workspace　is　predicted,　and　an　optimal　workspace　is　recommended.　With　the　index　of　global　dexterity　stiffness　index,　the　effects　of　design　parameters　on　the　global　performance　are　investigated.　This　study　can　be　further　extended　to　other　kinds　of　tripods,　thus　provides　useful　information　for　structural　optimization　and　rigidity　enhancement　of　the　tripod　modules.