Abstract: Summary  The planet gears in wind gearboxes are one of the key components which have direct inflection to gearbox life. This article mainly focuses on the situation where branched flower spots are found on the inner hole surface of planet gears during acid corrosion inspection after carburizing, quenching, and inner grinding processes. The planet gears are dissected and analyzed from multiple aspects such as material, hardness, and metallographic structure to evaluate the influence of branched flower spots on parts’ quality.