Cross-border e-commerce (CBEC) is the future trend of cross-border trade. Although China is at the forefront of CBEC development, its transaction volume is still not satisfactory. The purpose of this paper is to study factors influencing the development of CBEC industry from the macro-environment perspective. First, we commented and summarized relevant literature at home and abroad about business ecosystem and factors determining the development of CBEC, then proposed a model of factors influencing CBEC development by combining business ecosystem theory with PEST framework, followed by interpretation and discussion. The model consists of core species, key species, supporting species, parasitic species in the CBEC ecosystem, and they are affected by external environmental factors from political, economic, social and technological perspectives.