Abstract: Objective To collect data for comparative anatomy on the structure and distribution of the left bundle branch and Purkinje fiber networks in bovine heart. Methods The morphosis of left bundle branches and Purkinje fiber networks were observed after perfusing Chinese ink into 22 bovine heart gross specimens. The left -angle coordinate was built by the anterior and the posterior papillary muscles line as x-axis, and the main trunk of the left bundle branch serves as y-axis.Then the right ventricle was divided into four quadrants. The density of Purkinje fiber networks was measured by naked eyes and expressed with the number of signal“+”. Results The main trunk of the left bundle branch, which showed the flat band shape, ran along the sub-endocardium of the left part of inter-ventricular septum.It's length was 27.07±5.96 mm and it's width was 5.64±2.12 mm; There were three types in the first branch: shape of two branches(31.82%), shape of three branches (63.64%), and networks(4.55%); The density of Purkinje fiber networks of sub-endocardium in left ventricle varies in different quadrants .The types Ⅲ and Ⅳ quadrants mainly indicated “++”, 17 (77.27%) and 15 (68.18%)cases in them respectively; The typesⅠand Ⅱ quadrants mainly indicated “ +++”, and there were 12 (54.55%) and 9 (40.91%) cases in them respectively. Conclusion The structure and distribution of left bundle branch and it's Purkinje fiber networks of bovine heart is similar with human heart but there is some specificity for bovin heart.

Key words: Left bundle branch, Purkinje fiber, Bovine, Morphology