Soil waterlogging is one of the major abiotic stresses affecting maize growth and yields. To understand the molecular mechanisms underlying waterlogging tolerance in maize, the iTRAQ LC-MS/MS technique was employed to map the proteome of seedling root cells of the A3237 (tolerant inbred) and A3239 (sensitive inbred) lines under control and waterlogged conditions. Among the 3373 identified proteins, 293 were differentially abundant proteins (DAPs), of which 207 originated in A3237 and 158 in A3239. These DAPs were categorized into 11 groups that are closely related to plant defence responses, including metabolism, energy, disease/defense and transport. In the tolerant line A3237, NADP-malic enzyme, glutamate decarboxylase, coproporphyrinogen III oxidase, glutathione S-transferase TAU 25, glutathione dehydrogenase and xyloglucan endotransglycosylase 6 were specifically accumulated to manage energy, maintain pH levels and minimize oxidative damage in waterlogged root cells.