The work aims to study the thermal stability of polycarbonate (PC) after hot-water aging at 95 ℃. Apparent morphology of PC was analyzed by stereomicroscope and the thermal weight loss was analyzed in nitrogen. Degradation kinetics was analyzed by Freeman-Carroll method and Coats-Redfern method. Gel permeation chromatography was performed for analysis. The results showed that: PC had defects which became more and bigger with the hot-water aging time prolonged. The thermal stability decreased overall with hot-water aging time prolonged, the char residue increased, the relative molecular weight decreased, and the macromolecular chain degraded. The thermal stability of PC decreases after hot-water aging at 95 ℃.