Abstract: Through macroscopic observation, chemical composition analysis, fracture analysis, metallographic inspection, scanning electron microscopy and energy spectrum analysis, the reason for low transverse percentage reduction of areashrinkage of fracture MC11H connecting rod was analyzed. The results showed that during forging process of connecting rod, the metal at the center of big end, small end and 1/2 radius of the cross section of forging flowed around in the width direction of forging, resulting in short MnS inclusions intermittently distributed at big end of connecting rod, thereby the transverse percentage reduction of areashrinkage of MC11H connecting rod was reduced.