中文摘要：

明代言官以言为职，在履职时面临着双重风险：一是皇帝的威胁和摧抑，二是周边各种势力的打击报复。为保证言官尽职，明代确立了一些激励和保障机制，包括鼓励直言、慎选言官、畀以重权、给予重赏、严加考察以及相应的人身保护等。这些保障机制在一定程度上激励了言官不畏风险，恪尽职守，在明中期以前发挥了较好的作用。但由于专制体制下皇权决定一切，而明代皇帝素质又普遍低下，言官保障机制不断被破坏，言官的职业风险更为突出，致使言官群体在晚明时期不断分化蜕变，从一个侧面揭示了明代士大夫的悲剧命运。

英文摘要：

The duty of the supervisors in Ming Dynasty is to give suggestions. The supervisors faced up to two risks, the menace from emperor and the revenge from other officials. In order to protect them, some encouragement and security systems were built such as encouraging speech, selecting supervisors carefully, giving power and reward, inspecting strictly and protecting lives. These security systems encouraged the supervisors to devote themselves to their career regardless of risk in some degree. The supervisors＂ function gave full play during earlier period of Ming Dynasty. However, under the circumstance of emperor power deciding everything and disappointing quality of emperors, the security system was destroyed gradually and supervisors＇career risk was strengthened, which impelled supervisors to degenerate all the time during later Ming Dynasty. Therefore, the supervisors＇tragic destiny was reflected from this aspect.