The paracaval portion of the caudate lobe (PPCL), as the deepest anatomical unit of the liver, remains the ultimate challenge in hepatic surgery due to its complex vascular supply and anatomical configuration. In recent years, the promotion of the concept of portal territory-anatomic resection (PT-AR) which utilizes the tumor-bearing portal vein territory as the fundamental unit for segmental/subsegmental resection, is advancing hepatobiliary surgeons’ understanding of this region’s anatomy towards unprecedented levels of individualization and refinement. Through results of three-dimensional imaging analysis and synthesis of existing literature, this study demonstrates significant variations in PPCL vascular origins and reveals critical deviations from classical Couinaud segmentation boundaries. This study proposes a novel portal-territory classification system for PPCL, emphasizing dynamic intraoperative delineation of true portal boundaries via integration of preoperative 3D reconstruction, laparoscopic ultrasonography, and indocyanine green (ICG) fluorescence navigation. Surgical strategies based on classification-specific were developed to achieve dual objectives: complete oncological resection within target portal territories and maximal preservation of functional liver parenchyma.