1937年7月7日，中日戰爭爆發，由於實力上的懸殊，中國需要仰賴外援來支持抗戰，由於歐美各國的冷漠，故抗戰爆發後，蘇聯成為國民政府積極交涉的對象。但直到抗戰爆發，中蘇兩國並未有更進一步的協議與合作，因無論是中國還是蘇聯，彼此接觸的目的都是為了增加與日本交涉的籌碼。直到「七七事變」，國民政府眼見與日本已無法避免全面衝突的情況下，始積極地與蘇聯往來，雙方在1937年8月21日簽署了《中蘇互不侵犯條約》，並陸續派出政治、軍事要人前往蘇聯爭取援助。1937年9月，以楊杰為首的軍事代表團前往蘇聯作軍事援助上的交涉，之後國民政府數次派遣立法院長孫科等政府大員赴蘇面見史達林爭取援助，雙方持續就援助問題進行交涉到1939年中，此時蘇援成為中國最主要的外援。 期間中國與蘇聯雖達成幾次的貸款與軍火協議，雙方關係卻因國內外的事件而產生許多漣漪，從1939年底的國際聯盟開除蘇聯會籍案，中國在決議時投棄權票，令蘇聯十分不滿；1940-41年間的「新四軍事件」，國共問題激化下的蘇聯反應；1941年4月，蘇聯為了東部邊界的利益與安全與日本簽訂《蘇日中立條約》，互相承認滿州國及蒙古國的存在，作出侵犯中國領土主權的行為；1941年6月，德蘇戰爭爆發等。對中國來說，與蘇聯議約是項非常艱難的事務，但合約簽訂後，如何讓蘇聯履約以及維繫中蘇關係也考驗著國民政府的外交處理。 本文將研究範圍的定為抗戰前期，即為1937到1941年間的中蘇關係，這段時間是蘇聯援助中國最積極的時候，除了帳面上的援助數字條目以外，筆者更想探討有著蘇援作為中蘇外交的基礎之下，雙方為何沒有更進一步的合作？更進一步合作的阻礙又是什麼？深入梳理這些事件背景的過程。論述過程分為兩部份探討，一是外交部份，先敘述1937至1941年期間的中蘇關係中，中國對蘇的方針如何以及蘇援交涉。另一部份則針對中蘇軍事合作議題來探討，從蘇聯空軍的來華參戰、迪化飛機廠合作案以及蘇聯駐華軍事顧問三個議題切入，來看蘇聯對華援助的具體貢獻，並從中蘇雙方尋求合作的經過，歸納出雙方合作的阻力，以期能補充抗戰前期中蘇關係的發展歷史。

In July 7, 1937, the Second Sino-Japanese war broke out. Due to their disparities in military strength, China needed to rely on foreign aid in order to continue the war of resistance. As a result of United States and Europe not responding, the Soviet Union became one of the Nationalist Government’s major allies. Before the war, however, China and the Soviet Union had made initial contact. They didn’t have any further cooperation since both nations, by keeping contact, was trying to increase their bargaining chip for future negotiations with Japan. Until the "Marco Polo Bridge Incident", only when the Nationalist Government realized full-scale conflicts with Japan was inevitable, substantial progress in relationship with the Soviet Union was made. In August 21, 1937, the Nationalist Government signed the "Sino-Soviet non-aggression treaty", and sent political and military dignitaries to the Soviet Union for assistance. In September, 1937, a military delegation led by Yang Jie headed to the Soviet Union asking for military assistance. The nationalist government later dispatched government high officials several times meeting Stalin, with high expectation getting assistance from the Soviet Union. The two sides continued their negotiations until 1939, which at that time, the Soviet Union became China's main source of foreign aid. During the period, although China and the Soviet Union reached several loan and arms agreements, events from home and abroad generated many ripples for bilateral relations. Such as the case that occurred in 1939, when the Soviet Union was expelled from the League of Nations, China’s abstention made the Soviet Union utterly dissatisfied; between 1940 and 1941, the "New Fourth Army Incident" that intensified by the relationship between the KMT and the Communist party was also a concern from the Soviet Union. In April, 1941, the "Soviet-Japanese Neutrality Pact" was signed for the benefit and security of the eastern border, their mutual recognition of Manchukuo and Mongolia's presence led to acts of violating China's territorial sovereignty. After the German-Soviet war broke out in June, 1941, the Soviet Union became harder and harder to deal with. Nevertheless, agreements between two nations continued to be signed, whereas getting the Soviet Union to maintain compliance on the Sino-Soviet diplomatic deal but also a test to the Nationalist Government. This thesis will examine the early war stage namely Sino-Soviet relations during the 1937-1941 period, when the Soviet provided aid to China most actively. In addition to numerical entries on the books of the aid, I would like to explore more with Soviet aid as foundation under Soviet diplomacy. Why wasn’t there any further bilateral cooperation? What hampered further cooperation? The discussion is divided into two parts: the first part focuses on diplomatic level, which describes the first Sino-Soviet relations during the 1937-1941 period, and how China's policy toward the Soviet Union influenced the Soviet aid. The other part discusses military cooperation issues between the Soviet Union and China through three different angles: the Soviet Air Force fighting in China, Dihua aircraft factory joint project and the Soviet military advisers. From looking into specific contributions from the Soviet aid and the process of the two sides seeking cooperation, this thesis summarizes the difficulties of bilateral cooperation and aims to provide a complement for the development of the Sino-Soviet relations during the Second World War .