Abstract: The backward environment for the international scientific and technological cooperation in less developed countries not only directly afflicts the possibility for international cooperation, but also magnifies its negative effects through the interdependent decision-making process, and finally obstructs the progress of science and technology and the development of productivity. Starting with economical environment, cultural environment, policy environment, and legal environment, and by using SEM-PCA, the environment factors of international scientific and technological cooperation in less developed countries are creatively brought into the empirical study. The result indicated that (1) for the less developed regions, cultural environment has the greatest impact on their international scientific and technological cooperation, besides, talent quality and cultural fusion has already become the important advantage for gaining partners in international competition. (2) The possibility to conduct international scientific and technological cooperation does not depend on their economical environment. (3)The most important factor for attracting the countries or regions with technical advantages to cooperate with less developed regions is the stable and preferential national policies. (4)The most important factor that the partners cooperating with less developed regions concern is the opportunity to avoid legal risk and save transaction cost.

Key words: international scientific and technological cooperation, environmental dependence, SEM, PCA