Abstract: Using a sample of plant (Iris virginica, 50 in size) as an example, basic principles (and their nature) of the R-type principal components analysis are described from view points of probability and statistics. Discussions are also made about the basic concepts of the principal components and their variances, the relationship between the KLT (Karhunen-Loeve transformation) and the "R-factor analysis" and the scores of various principal components at corresponding sampling points as are mentioned in 《A Study on the Compression Processing of the CCT Data Gathered by land Satellites》