tMonolithic graphene fibers for solid-phase microextraction (SPME) were fabricated through a dimen-sionally confined hydrothermal strategy and their extraction performance was evaluated. For the fiberfabrication, a glass pipeline was innovatively used as a hydrothermal reactor instead of a Teflon-linedautoclave. Compared with conventional methods for SPME fibers, the proposed strategy can fabricatea uniform graphene fiber as long as several meters or more at a time. Coupled to capillary gas chro-matography (GC), the monolithic graphene fibers in a direct-immersion (DI) mode achieved higherextraction efficiencies for aromatics than those for n-alkanes, especially for polycyclic aromatic hydrocar-bons (PAHs), thanks to – stacking interaction and hydrophobic effect. Additionally, the fibers exhibitedexcellent durability and can be repetitively used more than 160 times without significant loss of extrac-tion performance. As a result, an optimum extraction condition of 40◦C for 50 min with 20% NaCl (w/w)was finally used for SPME of PAHs in aqueous samples. For the determination of PAHs in water samples,the proposed DI-SPME-GC method exhibited linear range of 0.05–200 g/L, limits of detection (LOD) of4.0–50 ng/L, relative standard deviation (RSD) less than 9.4% and 12.1% for one fiber and different fibers,respectively, and recoveries of 78.9–115.9%. The proposed method can be used for analysis of PAHs inenvironmental water samples