The creep behavior of directionally solidified (DS) superalloy IC10 was investigated under 192 MPa and 218 MPa at 980 ℃. Under the testing conditions, the marked creep characteristic of the superalloy is that the creep curve has a short primary and secondary stage and a long tertiary stage. Another creep characteristic is that the superalloy has excellent plasticity at high temperature. To study the creep behavior, the microstructure was observed by SEM and TEM. Different from other microstructure of Ni-base superalloys, superalloy IC10 forms incompletely rafted γ phase during the creep processes. To understand the creep deformation mechanism of superalloy IC10, the movement of dislocations was analyzed. The results show that the dislocations moving in the γ matrix and climbing over the γ precipitates is the main deformation mechanism under the experimental conditions.