The growth of fish, like other organisms, is a complicated process, and it is inadequate to describe the feature of growth in terms of the changes of individual characters (such as length and weight). When fish grows, there are increases not only in length and in weight, but also in height and these increases are closely interrelated. Based on the changes of multi-indices of body character, the authors describe the regularity of growth in fingerling silver carp by using the method of principal component ana...