In groin hernia surgery, the transversalis fascia and the extraperitoneal fascia should be regarded as two distinct membranous structures, yet their morphological description and terminology remain not fully unified. It is difficult to accurately understand their continuity and surgical significance by local anatomical observation alone. From the perspective of embryonic development, the membranous structures of the inguinal region can be divided into two parts: the “parietal membranous structures” attached to the abdominal wall and the “visceral membranous structures” enveloping organs or structures such as the urinary bladder and spermatic cord. The former mainly includes the transversalis fascia, extraperitoneal fascia, and parietal peritoneum, whereas the latter, depending on the region, mainly includes the umbilicovesical fascia and the urogenital fascia surrounding the spermatic cord. The naturally loose space formed between these two groups of membranous structures represents a relatively ideal operative plane for preperitoneal dissection and mesh placement. Understanding the membranous structures of the inguinal region according to developmental and anatomical characteristics may help standardize layer-by-layer dissection, reduce collateral injury, and improve surgical safety.