At 1073K the creep rate ε˚ of the Ni-base alloy Inconel 617 has been measured as a function of strain at different stresses. Several characteristics of the dislocation structure have been observed by TEM as a function of strain for three stresses of 107, 180 and 320 ㎫: in particular free dislocations (not bound into subgrain boundaries and tangles around carbide particles), subgrains and dislocation configuration in the subgrain boundaries. At 1073K the first creep rate increases with strain as like in solution hardened materials and subsequently decreases as like in pure materials. These creep curves have also a good agreement with results of measured values of dislocation structures at various stresses. Concluded that 1) creep behavior of IN 617 shows transition phenomena from class M to A with increasing stress and 2) creep rate and microstructure results reveal a interdependent relationship.