This study intends to research external factors of modern Chinese history through examining the actual condition of contemporary Chinese Students Studying in America(CSSAs) for the first half of the 20th century, who were young minds in Chinese to try to take up a positive attitude in overcoming aggression by foreign powers and their internal conflicts. It concretely focuses the whole attention on CSSAs` present or real condition and the influence after their return from abroad during the Nanjing Nationalist Government(NNG). Since the NNG, studying in the United States had increased and it had become the mainstream, especially, after the middle 1930s. This period is largely classified into three categories. Above all, the NNG handled everything that had to do with the study-abroad-system modification and the international student management from June in 1928 to July in 1937. The next period was until August in 1945 and, at the same time, there were the Sino-Japanese War and the Pacific War. In this period, the CSSAs could apparently developed in terms of both quality and quantity. Lastly, the number of students steeply, even explosively increased for two years after the war. In this period, studying in the U.S. was not the actual purpose for learning but the academic flight for each individual safety. The NNG directly supervised to select students studying abroad. It also controlled their courses as well as disciplines. It could contribute to reducing some rash study abroad and gaining greater efficiency. However, it is difficult for students to learn and adopt Western civilization because of the excessive interferences and restrictions. It caused studying overseas to be transmuted into a way of pursuing personal wealth and fame rather than chasing the opportunities for creative and challenging progress. In the ruling period of the NNG, most Chinese students in America acquired diverse modern knowledge and technologies. They, in addition, went through the Western advanced culture for themselves, overcoming a lot of hardships. That is why they were able to transplant and foster modern civilization everywhere, which was especially prominent in the educational, political or governmental, and specialized-job world when they returned to China. Their several new cultures and thoughts derived from the West, precisely America, formed the basis of the modern Chinese. The CSSAs were primarily the upper class and mostly came from the coast of China, while there were very a few students from its interior or border. Furthermore, it made inequitable distribution of social and human resources intensify by settling in some big cities, mainly situated on China`s coast. A study abroad brought about the result of aggravating the imbalance or disharmony between regions and classes and led to another social conflict. Nevertheless, in the first half 1900s, they were a sort of leaders for an intellectual interchange, introducing and accepting Western civilization into China. They also were a kind of agents for the cultural exchange between the East and the West, spreading their valuable experiences through living abroad over their native country.