Objective To compare minimal invasive anterior plating osteosynthesis (MIAPO) and conventional plating osteosynthesis in terms of influence on the blood supply to the middle and distal third humeral shaft.Methods Six pairs of freshly frozen cadaveric specimens of human upper limb were used for this study.They were from 4 males and 2 females who were 54 to 87 years of age (mean,68.3 years).Each pair had one left and one right upper limb.After MIAPO and conventional plating osteosynthesis were used randomly on the left or right side in each pair of specimens,latex-red lead was then injected through the axillary artery.X-ray and anatomic examinations were conducted to observe the paths and disruptions of main vessels in the middle and distal third humeral shaft.Results There was one main nutrient artery entering the humeral shaft at the anteromedial (83.3%) and medial (16.7%) aspects.MIAPO did not damage the accessory nutrient arteries (altogether 17) at the back of the humeral shafts (0) while the conventional posterior approach damaged them more or less at different levels (9,52.9%).MIAPO also showed superior periosteal filling compared with the conventional posterior approach (significantly better in 3 pairs,moderately better in 2 pairs and mildly better in one pair).Conclusions Compared with the conventional plating,MIAPO leads to less disruption to the blood supply to the middle and distal third humeral shaft while it avoids intraoperative iatrogenic injury to the radial nerve. Key words: Humerus fractures; Surgical procedures, minimally invasive; Fracture fixation, internal; Perfusion