【Abstract】 Objective To observe the distribution feature of nerve bundles in C7 nerve anterior and posterior division end. Methods The brachial plexus specimen was harvested from 1 fresh adult cadaver. After C7 nerve was confirmed, the distal end of anterior and posterior division was dissected and embedded by OCT. Then the samples were serially horizontally sliced with each 10 μm deep. After acetylcholinesterase (AChE) histochemical staining, the stain characteristics of different nerve fiber bundles were observed and amount of the nerve fiber bundles were counted under optic-microscope. At last, the imaging which were collected were three-dimensional (3-D) reconstructed by using Amira 4.1 software. Results There was no obvious difference in the stain between the anterior and posterior divisions. The running of the nerve fiber bundles were dispersive from proximal end of nerve to distal end of nerve. Nerve fiber bundles of anterior division were mainly sensor nerve fiber bundles, which located in medial side. Nerve fiber bundles of posterior division were mainly moter nerve fiber bundles, having no regularity in the distribution of nerve fiber bundles. The total number of nerve fiber bundles in distal end of anterior division was 7.85 ± 1.04, the number of motor nerve fiber bundles was 2.85 ± 0.36, and the number of sensor nerve fiber bundles was 5.13 ± 1.01. The total number of nerve fiber bundles in distal end of posterior division was 9.79 ± 1.53, the number of motor nerve fiber bundles was 6.00 ± 0.69, and the number of sensor nerve fiber bundles was 3.78 ± 0.94. There were significant differences in the numbers of motor and sensor nerve fiber bundles between anterior and posterior divisions (P lt; 0.05). The microstructure 3-D model was reconstructed based on serial slice through Amira 4.1. The intercross and recombination process of nerves bundles could be observed obviously. The nerve bundle distribution showed cross and combination. Conclusion Nerve fiber bundles of anterior division are mainly sensor nerve fiber bundles and locate in medial side. Nerve fiber bundles of posterior division are mainly motor nerve fiber bundles, which has no regularity in the distribution of nerve fiber bundles. The 3-D reconstruction can display the internal structure feature of the C7 division end.