Background: Laparoscopic liver resection (LLR) has been considered to be safe and feasible.However, few studies focused on the comparison between the anatomic and nonanatomic LLR.Therefore, the purpose of this study was to compare the perioperative factors and outcomes of the anatomic and nonanatomic LLR, especially the area of liver parenchymal transection and blood loss per unit area.Methods: In this study, surgical and oncological data of patients underwent pure LLR procedures for malignant liver tumor were prospectively collected.Blood loss per unit area of liver parenchymal transection was measured and considered as an important parameter.All procedures were conducted by a single surgeon.Results: During nearly 5 years, 84 patients with malignant liver tumor received a pure LLR procedure were included.Among them, 34 patients received anatomic LLR and 50 received nonanatomic LLR, respectively.Patients of the two groups were similar in terms of demographic features and tumor characteristics, despite the tumor size was significantly larger in the anatomic LLR group than that in the nonanatomic LLR group (4.77 ± 2.57 vs.2.87 ± 2.10 cm, P =0.001).Patients who underwent anatomic resection had longer operation time (364.09 ± 131.22 vs.252.00 ± 135.21 min, P ＜ 0.001) but less blood loss per unit area (7.85 ± 7.17 vs.14.17 ± 10.43 ml/cm2,P =0.018).Nonanatomic LLR was associated with more blood loss when the area of parenchymal transection was equal to the anatomic LLR.No mortality occurred during the hospital stay and 30 days after the operation.Moreover, there was no difference in the incidence of postoperative complications.The disease-free and overall survival rates showed no significant differences between the anatomic LLR and nonanatomic LLR groups.Conclusions: Both anatomic and nonanatomic pure LLR are safe and feasible.Measuring the area ofparenchymal transection is a simple and effective method to estimate the outcomes of the liver resection surgery.Blood loss per unit area is an important parameter which is comparable between the anatomic LLR and nonanatomic LLR groups.