This study focuses on Joseph W. Stilwel1's reports to U.S. War Department in the period of 1935 to 1939. Stilwell's evaluation and prediction in his reports has some unbelievable high lights as well as some prejudicial criticisms to Chinese people and to some political figures especially to Marshal Chiang Kai-shek. This study collects all of Stilwell's reports and points the evidence of his prejudice in his own writings. It is hopeful that this study could help to clear ax ay some suspicions in the modem Chinese history.