孫中山欲推動革命，需要基地，需要財源，也需借重國際化的現代化經驗，這些都是他樂於接受日本援助的理由。也因日本政府的支持，孫得以收編中國南方的各秘密會黨，奠定了他成為秘密會黨代表的領袖地位。所以，從孫中山的角度言，中國革命能夠成長與茁壯，日本確有實質的貢獻。對日本而言，甲午戰後，東洋大國的舊中國形象，仍舊深植人心。再則，1896年當中俄兩國已締結軍事同盟條約之傳聞，在國際社會廣被渲染之際，更使日本惶恐不安。為了預防清廷政府的報復，支持孫中山的革命運動以便牽制清廷，便成為日本政府的國策。 正因為雙方關係之接合，是基於各自利益的考量。因而，客觀情勢的變遷，即影響雙方關係的發展。1900年的義和團之亂，是雙方關係面臨調整的第一步。1905年的日俄戰爭，是第二步。 義和團之亂使日本政府深信清廷已病入膏肓，再也不足為心腹之患。但鑑於中國已淪為次殖民地，在列強紛紛進入中國爭相角逐建構勢力範圍之際，為了避免西方列強在蠶食中國後進而直逼日本，提倡中國領土完整，即成為此時刻的日本對華新政策。由於新的對華政策轉變為扶植清廷恢復國內秩序，寄望中國能成為日本與西方列強之間的緩衝地帶，因而此一時期日本政府開始正式切斷對孫中山的援助。 日俄戰爭的結果，讓日本勢力進入中國。如何繼續拓展日本在中國東北的特殊權益，就成為日本政府的新指標。為了順利執行此一新目標，日本政府開始放棄提倡中國領土完整政策。此外，更以扶植清廷執政為首要考慮。換言之，當蠶食中國領土主權已成為日本政府既定國策時，日本政府當然不希望中國有所改變。是以，腐化的清廷政府，最足以滿足日本政府的所欲所求。為了維護清廷的執政，日俄戰後的日本政府開始逐步鎮壓以日本為基地的中國革命運動。 辛亥革命期間，日本政府對華政策可分為兩個階段：前期是保皇政策，這是延續日俄戰後以來的一貫政策；後期是利權外交，日本政府以「貸款」為餌，誘使南京政府出賣長江流域之商業特權。 不能順利爭取到日本政府的實質援助，是孫中山在辛亥革命後期被逼與袁世凱謀求妥協的關鍵。日本政府不能趁孫中山最需外援之際，與孫中山的革命勢力建立起相互扶持的合作關係，也促使雙方關係一直停留在吳越同舟的瓶頸，完全沒有突破的空間。

In order to facilitate his revolutionary activities, Sun Yat-sen needed a baseand financial support, as well as experience of the modernization process from the advanced countries. These were all incentives for him to accept Japanese aid. Due to the support of Japan, Sun was able to merge the various secret societies in South China and became their leader. Japan thus helped the Chinese revolution in its early stage. From the Japanese point of view, China’s conventional image as a huge empire had survived the Sino-Japanese War. Furthermore, Japan was anxious at the rumored possibility of a Sino-Russian military coalition. In order to prevent revenge from the Qing, Japan chose to support Sun’s revolutionary activities as a containment policy. Since the foundation of the cooperation between Sun and Japan was based on mutual benefit, changes in circumstances could challenge it. Two key events brought about such a change. One was the Boxer Uprising in 1900, and the other was the Russo-Japanese War in 1905. The Boxer Uprising convinced Japan that the Qing was no longer a threat. Finding that China had become a kind of colony, Japanese policy shifted to the protection of China from dismemberment by Western powers. Japan’s new China policy switched to support the Qing Imperial House to maintain order, so as to be strong enough to maintain a buffer state between Japan and Western powers. Accordingly, in this period Japan terminated its support to Sun. After the Russo-Japanese war, Japan further aggrandized her influence into China. The expansion of its special interests in Manchuria became Japan’s essential goal. Therefore Japan abandoned its traditional policy of supporting the unity of China, while, on the other hand, firmly supporting the Qing government. This is because after its victory over Russia, Japan believed in its capability of competing with Western powers in the dismemberment of China. To meet this purpose, the existence of a corrupt Qing government was to its advantage. As a result, Japan adopted a policy of suppressing the revolutionaries. As for the period of the 1911 Revolution, Japan’s China policy can be further divided into two stages. At first, Japan, following her post Russo-Japanese War policy, backed the Qing Imperial House. Later, Japan proposed a loan to the revolutionary government in exchange for commercial privileges in the lower Yangtzu Valley region. Failing to acquire substantial aid from Japanwas a key factor in forcing Sun Yat-sen to compromise with Yuan Shikai. On the other hand, Japan as well missed its best chance to establish cooperative relationship with Sun’s revolutionary forces. Their relationship thenceforce remained mistrustful.