High-temperature creep experiments were made on olivine single crystals under compressional stress to large strains. At strains larger than about 40 to 60%, dynamic recrystllization occurs and cellular wall dislocation structure is formed. Recrystallized grain size dg(&mgr;m) and cell wall spacing ds(&mgr;m) are dependent upon applied stress &sgr;(MPa) as: dg?(times)=103&sgr;1.18¿0.11 and ds?(times)=102&sgr;-0.67¿0.10.