In order to balance the freedom of investment and environment protection，some early environment treaties adopt some investment regulations as a part of the treaties. Recently，it is distinguishing feature that some international agreements adopt some environment regulations.The legislative patterns experience from investment agreement to freedom trade agreement. The content of the international investment agreements develop from substantive regulations to procedural regulations and illustrate the trendof imposingrights and obligations directly on multinationals. Under this background，therearesome important changes in international investment agreements which China has already concluded with other countries. However，these agreements have some weak points and needto be perfected in every aspect.