Objective To study the efficacy and safety of EndoClot polysaccharide hemostatic system (EndoClot PHS) for heparinized arterial hemorrhage of upper digestive tract (Forrest Ⅰa) in animal model. Methods Twelve experimental pigs were randomly divided into the test group (n=6) and the control group (n=6) by simple random grouping method. Gastric arterial hemorrhage models were established. Endoclot PHS and Hemospray were used to spray on the wound to stop bleeding in the test group and the control group respectively. The time of effective hemostasis, the amount of hemostatic particles used, and the blockage of the powder feeding tube and its replacement were compared between the two groups. The survival and complications of experimental pigs were observed after the operation. In 10 days after the operation, the experimental pigs were euthanized for pathological dissection. Results Spurting or pulsatile bleeding was achieved in all experimental pigs. There were significant differences in the time of effective hemostasis (8.75±0.84 min VS 9.83±0.62 min, t=-2.53, P=0.030) and the amount of hemostatic particles used to achieve effective hemostasis (6.71±0.39 g VS 14.10±1.62 g, t=-10.86, P<0.001) between the test group and the control group. There was no significant difference in the occurence of clogging or the replacement of powder feeding pipes between the two groups (0.64±0.02 times VS 0.67±0.04 times, t=-1.64, P=0.131). In addition, the gas source of the test group was stable, and the visual field under the endoscope was clear. Neither the test group nor the control group had gastric lesions, perforation, or embolism. The blood glucose, blood routine, and liver and kidney functions were normal, and no thrombosis or embolism of the main organs occurred in either group. Conclusion EndoClot PHS is safe and effective for heparinized upper gastrointestinal arterial hemorrhage (Forrest Ⅰa) in animal models.