Let T be a locally finite triangulated category with an autoequivalence F such that the orbit category T /F is triangulated. We show that if X is an m-cluster tilting subcategory, then the image of X in T /F is an m-cluster tilting subcategory if and only if X is F -perodic.We show that for path-algebras of Dynking quivers ∆ one may study the periodic properties of n-cluster tilting objects in the n-cluster category Cn(k∆) to obtain information on periodicity of the preimage as n-cluster tilting subcategories of D b (k∆).Finally we classify the periodic properties of all 2-cluster tilting objects T of Dynkin quivers, in terms of symmetric properties of the quivers of the corresponding cluster tilted algebras EndC 2 (T ) op . This gives a complete overview of all 2-cluster tilting objects of all orbit categories of Dynkin diagrams.