Abstract: Grouted sleeve connections (GSCs) have been widely used in precast concrete (PC) structures. Insufficient grouting of GSC is the main factor affecting the seismic performance of PC shear walls (PCSWs). To investigate the influence of grouting defects on seismic performance of PCSWs, tests of both GSCs and full-scale PCSWs were conducted. At the connection level, considering the effect of four defect ratios, five GSCs were manufactured for large deformation cyclic test. Through the comparison between the specimens without and with defects, the influences of defect ratio on mechanical behavior and failure modes of GSCs were identified, and the threshold of defect ratio when bar-slip failure occurs was revealed. At the component level, based on the test results of GSCs, two full-scale PCSWs were tested under cyclic loads, including one specimen without defects and one with a defect ratio of the threshold. The failure mode, strength, deformation and energy dissipation capacities of two specimens were compared and analyzed. The test results indicated that: For the rebar with a diameter of 12 mm, according to the test results, the GSC with a defect ratio close to 60% exhibited the bar-slip failure mode when the tensile strain of rebar reached approximately 2 times of the yield strain. The strength rapidly degraded after the occurrence of bar slip, and the ductility of this GSC was significantly lower than that of other GSCs. The PCSW with a defect ratio of 60% exhibited the expected bar slip soon after the yielding of the longitudinal rebar, rather than the flexural failure with the strain of rebar reaching approximately 2 times of the yield strain. After the occurrence of bar slip, significant rocking deformation characteristic was observed for the specimen with defects, leading to lower strength, deformation and energy dissipation capacities in comparison with the specimen without defects.