本文分為五節:第一節介紹政黨滲透清華的經過。由於清華地處郊區，又有傳統學術自由的保障，故易為共黨所滲透。這就是清華能從五四時期之後知後覺，轉變為一九三○年代之先知先覺，成為全國學生運動領袖的原因。 第二節談清華與九一八救亡運動，由於這時尚無顯明的政黨介入，可以說是一次純正的愛國運動。但在高漲的民族主義情緒下，清華地下黨又活躍起來，為下一波運動作好準備。 第三節介紹1935年底之一二九學生救國運動及其後一年之相關活動。因其影響遍及全國，為中共之取得政權奠立根基，受到今日大陸各大學校史編者的高度評價。但本人研究發現，這一運動因受到清華中共地下黨份子的影響，行動偏激，以救國之美名，行挽救逃竄中共黨之實，為國民政府增添極大的麻煩。 第四節從外鬥到內鬥，陳述清華校園內部不斷發生左派學生和教授的衝突，以及學生之間的左右派衝突，嚴重破壞校園安定發展的情形。 第五節從檯棺遊行至西安事變，除說明學生行為粗魯，思想左傾冒進外，亦指出張學良支持一二九運動，以達到逼蔣抗日，挽救中共之危的目的。 最後為結論，對學生運動尤其是一二九運動重新評價。本人認為學生運動是時代的病態，學生之政治性運動多為在野政黨所煽惑利用，及其一旦取得政權，必然轉過頭來壓制學生運動，故學生始終是輸家，不值得鼓勵。至於一二九運動，本人認為它名義上救國，實質上則是誤國。

　　　　　There are five sections in this paper. Sect. 1 describes how the Chinese Communists were able to infiltrate TsingHua University. The Communists' infiltration revolutionized the students' attitude toward political movement outside campuses. This was the main cause that made TsingHua University students leaders of student movements in the nation. Sect. 2 shows that the involvement of TsingHua University students in the September Eighteenth Anti-Japanese Aggression demonstration which occurred throughout China in 1931. Though these student parades were basically patriotic in nature, they escalated the feeling of nationalism to such a degree of no return that the Communist infiltrators were provided with an excellent opportunity to develop their organizations in the universities. Sect. 3 shows that it was the TsingHua University leftwing students who, in order to rescue the Communists from being eliminated, took the initiative to organize students in Peking to demonstrate on December the Ninth of 1935, and to urge the Government to fight against the Japanese invaders. In so doing, the students pushed the National Government into a dilemma. Sect. 4 describes the political struggles between students and professors, and those between the leftwing and rightwing students. These political struggles caused turmoil on the TsingHua University campus. Sect. 5 shows that the students rushed into extremes forcing the Government to fight immediately against the Japanese, which led to the Sian Incident and the Sino-Japanese War. This War gave the Chinese Communists an excellent opportunity to develop and to become strong enough to overthrow the KMT Government. In my final analysis, the December Ninth Student Movement was patriotic in name only. It was harmful to the nation in reality.