Based on the presentation of the scope, principal subjects and structure of BAHC (Biospheric Aspects of Hydrological Cycle), the Core Project of IGBP (International Geosphere-Biosphere Project), the progress of BAHC is introduced in this paper, and in the light of its research status quo and development trend, the new theme and focuses of BAHC in future is also discussed. The content of this paper includes following three parts: Part 1:Outline of BAHC——consists of following two contents: 1. The ...