The degradation of microstructure and property in turbine blades of aircraft engines is inevitable during their service. Usually, rejuvenation heat treatment is applied to regenerate the original microstructure for extending the service life of blades and improve economic returns. To date, systematic investigations about rejuvenation heat treatment of the directionally-solidified superalloys are limited. In this work, the effect of rejuvenation heat treatment on the degraded microstructure and property of DZ125 superalloy damaged by creep was investigated. The interrupted creep test was first conducted on DZ125 superalloy to simulate the damage of turbine blades during their service. Three rejuvenation heat treatments with the solution temperature at 1230, 1240 and 1250 ℃ were applied to the interrupted creep specimen. Then, the rejuvenated specimens were retested, and their microstructures as well as creep properties were compared with those of the initial interrupted creep tests. The results showed that no recrystallization occurred after the interrupted creep tests at 1.0% and 3.5% strain followed by rejuvenation heat treatment, and the critical strain for the formation of the recrystallization was between 3.5%~10.0%. The solution treatment at 1230 ℃ partially dissolved the coarse γ' phase caused by creep deformation, caused a nonuniform microstructure of γ /γ' matrix after aging treatments, and resulting in partially recovering the baseline creep property. However, the solution treatment at 1240 and 1250 ℃ could not only dissolve the coarse γ' phase but also reduce the fraction of residual γ' eutectic significantly, and then regain a uniform microstructure of γ /γ' matrix after aging treatments. Hence, the effect of rejuvenation was further improved, maintaining or exceeding the baseline creep property.