  In this paper, we studied the research areas of Chinese natural science basic
research from a point view of complex network. Two research areas are
considered to be connected if they appear in one fund proposal. The explicit
network of such connections using data from 1999 to 2004 is constructed. The
analysis of the real data shows that the degree distribution of the {\bf
research areas network} (RAN) may be better fitted by the exponential
distribution. It displays small world effect in which randomly chosen pairs of
research areas are typically separated by only a short path of intermediate
research areas. The average distance of RAN decreases with time, while the
average clustering coefficient increases with time, which indicates that the
scientific study would like to be integrated together in terms of the studied
areas. The relationship between the clustering coefficient $C(k)$ and the
degree $k$ indicates that there is no hierarchical organization in RAN.
