Abstract: Proper structural index systems at three levels for classifying agroecosystem and methods for converting various indices into same unit were discussed in this paper. Based on the data obtained from some typical ecological farms in different areas of Zhejiang Province,5 data transformation techniques and effective methods for unifying the dimension of various indices and reducing great disparities in quantity among the indices were studied and discussed.

Key words: Agroecology, Index system, Characteristic number, Cluster analysis, state transition, NPQ., photosystem, LHCⅡ phosphorylation