<p>Imperfections in the bonding of bolts to the rock mass (such as anchorage defect and joint) are critical to the time-dependent anchoring performance. The poor load transmission resulted from imperfections may exacerbate the damage resulting from the creep behavior of rock. In this paper, the laboratory experiments were performed to explore the creep instability mechanism in bolt-reinforced specimens, especially in the context of inadequate anchoring quality-induced anchorage defect. Four specific experimental schemes regarding the bolt and anchorage defect were established under creep loading. The crack-arresting effect of the bolt is actively mobilized, especially in steady-state and accelerated creep stages of specimen. The stability of specimens with imperfections under creep loading are primarily controlled by joint and although the small-scale anchorage defect has minimal impact on strength of bolt-reinforced specimen, it substantially reduces long-term stability and increases time-dependent cracking in specimen. In comparison to the end-anchorage defect, the anchorage defect that interacts with the joint has a more significant impact on the time-dependent instability and the initiation of micro tensile cracks in bolt-reinforced jointed specimens. This is due to its tendency to produce lower bolt strain, less effective energy storage capacity, and greater occurrence of high-frequency acoustic emission events within the specimen. In addition, the failure mechanism under different strain rates is revealed. More specifically, the evolution of cracks in specimens subjected to low strain rate loading closely resembles that observed under quasi-static loading. Bolt effectively arrests cracks by suppressing the propagation of primary tensile wing cracks, while anchorage defect primarily affects the failure of the specimen by altering the direction of the primary shear cracks. This paper seeks to deepen the understanding of creep instability mechanisms triggered by imperfections, and also offers theoretical basis for the prevention of resin loss in jointed rock mass.</p>